Industrial Drive Bike Connection Feasibility Study and ...

Industrial Drive Bike Connection Feasibility Study and Conceptual Design Plan

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Industrial Drive Bike Connection

Feasibility Study and Conceptual Design Plan

June 2020


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Table of Contents 1. Introduction ................................................................................................................................................... 4

2. Relevant Planning Studies and References ...................................................................................................... 5

3. Existing Area Characteristics .......................................................................................................................... 6

3.1. Zoning and Land Use .............................................................................................................................. 6

3.2. Right of Way and Topography ................................................................................................................ 7

3.3. Existing Trails and Roadways ................................................................................................................. 8

3.4. Existing Lighting .................................................................................................................................... 8

4. Additional Data Collected .............................................................................................................................. 9

4.1. Forest Conservation Easements ............................................................................................................... 9

4.2. Utility Easements.................................................................................................................................... 9

4.3. Tree Inventory .......................................................................................................................................10

4.5. Wetlands delineation .............................................................................................................................11

5. Design Concepts ...........................................................................................................................................12

5.1. Design Assumptions ..............................................................................................................................12

5.2. Additional Design Requests ...................................................................................................................13

5.3. Design Concept Segments .....................................................................................................................13

5.4. Conceptual Designs for the Northern Segment .......................................................................................14

5.5. Conceptual Design the Southern Segment ..............................................................................................17

5.6. Conceptual Design for the Central Segment ...........................................................................................18

5.6.1. Conceptual Design for Option 1a along the Central Segment ..............................................................19

5.6.2. Conceptual Design for Option 1b along the Central Segment .............................................................21

6. Construction and Maintenance Costs for each Option ....................................................................................24

6.1. Northern Segment Construction Cost .....................................................................................................25

6.2. Southern Segment Construction Cost .....................................................................................................25

6.3. Central Segment Construction Cost ........................................................................................................25

6.4. Construction Cost Summary for the Bike Facility ..................................................................................26

6.5. Maintenance and Final Design Cost .......................................................................................................27

7. Community Input ..........................................................................................................................................27

7.1. Intra-agency Input .................................................................................................................................29

8. Recommended Option and Design Details .....................................................................................................29

8.1. Design Details to be explored during Final Design .................................................................................32

8.1.1. Stormwater Facility Design ................................................................................................................32

8.1.2. Boardwalk Slope and Design .............................................................................................................34

8.1.3. Lighting .............................................................................................................................................35


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8.1.4. Wayfinding ........................................................................................................................................35

8.1.5. Additional Design Notes ....................................................................................................................35

9. Implementation and Funding Strategies .........................................................................................................35

10. Summary and Next Steps ...........................................................................................................................36

10.1. Next Steps .........................................................................................................................................37

List of Figures

Figure 1: Bike Path Study Area ............................................................................................................................. 4 Figure 2: Proposed Breezeway Network Plan (Montgomery County Bicycle Master Plan, Dec. 2018) ................... 6 Figure 3: City of Gaithersburg Zoning ................................................................................................................... 7 Figure 4: Study Area, with ROW lines (red) and topography ................................................................................. 8 Figure 5: Forest Conservation Easements and Utility Easements ..........................................................................10 Figure 6: Map of the study area, divided into three segments ................................................................................14 Figure 7: Two conceptual alignments for the Northern Segment ...........................................................................15 Figure 8: Narrow Path between Morris Park and Summit Hall Elementary, looking east .......................................15 Figure 9: Proposed typical cross section of a widened path between Morris Park and Summit Hall Elementary ....16 Figure 10: Existing Sidewalk along northbound Summit Hall Road, looking south ...............................................16 Figure 11: Industrial Drive looking south from its northern terminus toward the I-370 overpass ...........................17 Figure 12: Proposed Typical Section for Industrial Drive south of the cul de sac ..................................................18 Figure 13: Examples of commercially available vertical bike buffers ....................................................................18 Figure 14: Conceptual Routes for Options 1a, 1b, and 2, along the Central Segment of the Bike Facility ..............19 Figure 15: Worn trail looking north from warehouse parking lot toward Mudd Branch bridge ..............................20 Figure 16: Existing Bridge of Muddy Branch, looking south ................................................................................20 Figure 17: Example of a prefabricated-structure truss bridge ................................................................................21 Figure 18: Alignment of Option 1b in the Central Segment ..................................................................................21 Figure 19: Photo along option 1b, 30 feet south of the Muddy Branch stream, looking north toward Morris Park..22 Figure 20: Option 2 alignment for the Central Segment ........................................................................................23 Figure 21: Example of boardwalk over wetlands in a stream valley (Patuxent River Trail, Howard County, MD) .24 Figure 22: Standard detail for Boardwalk Support (source: Montgomery Parks) ...................................................26 Figure 24: Zip code of survey respondents ...........................................................................................................28 Figure 24: Public survey results............................................................................................................................29 Figure 25: Example of non-rooftop disconnect (source MDE Stormwater Guidelines) ..........................................33 Figure 26: Example typical section of a shallow depth side swale .........................................................................33 Figure 27: Rain garden typical section (source: Montgomery County DPS) .........................................................34

List of Tables

Table 1: Observed Plant Species List....................................................................................................................11 Table 2: Range of Construction Costs for all Alignments......................................................................................27 Table 3: Comparison of Alignment Impacts .........................................................................................................30 Table 4: Comparison of each alignment within the Central Segment of the Study Area .........................................31 Table 5: Approximate SWM requirements calculation for the proposed design options.........................................34


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APPENDICES

Appendix A: Existing Conditions Map, Tree Inventory and Waters of US

Appendix B: USFWS IPAC Report & DNR letter regarding any rare, threatened, and endangered species

Appendix C: Wetlands Photos

Appendix D: Conceptual Option 1a, 1b Appendix E: Conceptual Option 2

Appendix F: Cost Estimate Details

Appendix G: Community Feedback Appendix H: 10% Design, Recommended Option

Appendix I: Forest Conservation Easement and Agreements

Appendix J: Annexation Agreement X-13


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1. Introduction The City of Gaithersburg is striving to improve biking and walking accessibility of its communities and to add

connectivity to local resources (parks, schools, businesses, etc.) by constructing trails, sidewalks, and bike

infrastructure. Major highways are often barriers separating neighborhoods and local attractions, such as employment centers, public parks, schools, concentrated retail areas, and transit hubs. Currently I-370 is a barrier between two

adjoining neighborhoods, preventing easy and direct access. Industrial Drive is a 50-foot wide, two-lane overpass

that bridges I-370 and has the ability to provide the means for connecting these neighborhoods. Industrial Drive

terminates at Gaither Road in the south and at a cul-de-sac and City-owned woodlands to the north. On the other side of these woodlands is a City Park, local elementary school, and West Deer Park Road – which has direct access to a

trail network connecting multiple neighborhoods and additional public amenities (See Figure 1). By making a

connection from Industrial Drive, through the woodlands, to West Deer Park Road, two adjacent neighborhoods of the City can be joined in a safe and accessible manner for walkers and cyclists. This effort will help the City move

toward its stated Master Plan goal of a “…well–maintained, multimodal transportation system facilitates the safe,

convenient, affordable, and efficient movement of people, goods, and services within and between population and

business centers.”

Figure 1: Bike Path Study Area

The purpose of this study is to produce up to three alternatives for bikeable facilities, select a preferred option,

develop it to 10% design detail, and document all findings and assumptions in this feasibility report for use during the 30% Design phase.


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2. Relevant Planning Studies and References Several resources were utilized in the development and analysis of the preliminary concepts:

• Montgomery County Bicycle Master Plan, Approved and Adopted December 2018.

• City of Gaithersburg 2003 Master Plan, Adopted August 2004. o 2009 Transportation Element, adopted September 2010. Chapter 6: City Bicycle and Pedestrian Plan

• City of Gaithersburg Tree Manual.

• Maryland State Forest Conservation Technical Manual, Third Edition, 1997.

o Incorporated in the City of Gaithersburg Tree Manual

• City of Gaithersburg Environmental Standards for Development Regulation, May 2010.

Montgomery County Bicycle Master Plan, Approved and Adopted December 2018

The Montgomery County Bicycle Master Plan is a comprehensive update and amendment to all existing County bike

plans, including the 1978 Master Plan of Bikeways, the 2005 Countywide Bikeways Functional Master Plan, and

bikeway recommendations in past functional plans, master plans, and sector plans. The Montgomery County Bicycle Master Plan is a “key element in Montgomery County’s Vision Zero Two-Year Action Plan to eliminate traffic-

related fatalities and serious injuries”. The Montgomery County Bicycle Master Plan contains recommendations for

a low stress network of bikeways and bicycle infrastructure throughout Montgomery County, including creation of a Breezeway Network, a high capacity system of arterial bikeways between major activity centers.

The Gaithersburg Bicycle Connection Feasibility Study supports the planning priorities outlined in the Montgomery

County Bicycle Master Plan, specifically for the Derwood Area of the county. This project will provide a low stress off-road bicycle facility that connects parts of the City of Gaithersburg located on the north side of Interstate 370 to

activity centers on the south side and to the breezeway network.

City of Gaithersburg 2003 Master Plan; 2009 Transportation Element, adopted September 2010

Chapter 6 of the 2009 Transportation Element of City of Gaithersburg Master Plan reference goals and planning

objectives related to increasing pedestrian and bike accessibility and connectivity. Specifically, the plan identified connecting to elementary schools, parks and the Shady Grove Metro Station as important origins or destination.

Additionally, I-370 was referenced in the plan as a barrier to connectivity. Finally, the 2009 Transportation Element

of the Master Plan proposes an-off path connecting Industrial Drive to Morris Park1.

Maryland State Forest Conservation Technical Manual, Third Edition, 1997

The Maryland State Forest Conservation Technical Manual sets a baseline of required thresholds for forest

preservation and mitigation for development projects.

City of Gaithersburg Tree Manual

The City of Gaithersburg Tree Manual presents methods for preservation of the City's existing trees and forest, as well as the creation of new landscapes, and is specifically designed to adequately offset the negative environmental

impacts of urbanization. This manual outlines procedures for compliance with Chapter 22 of the City Code, which

seeks to preserve, protect, and improve the health and general welfare of the public by promoting the environmental

and public benefits of saving, maintaining, and planting trees and forested areas. Observations and inventory of the existing conditions and environmentally sensitive resources within the study area were prepared using the guidance

and procedures outlined in this manual.

City of Gaithersburg Environmental Standards for Development Regulation, May 2010

The City of Gaithersburg Environmental Standards were developed as a comprehensive set of guidelines that set

standards for environmental protection and practices that support watershed management and health. Observations

and inventory of the existing conditions and environmentally sensitive resources and development of associated buffers within the study area were prepared using the guidance and procedures outlined in this manual.

1 City of Gaithersburg Master Plan, 2009 Transportation Element. Page 32, Map 7. Adopted September 2010


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Figure 2: Proposed Breezeway Network Plan (Montgomery County Bicycle Master Plan, Dec. 2018)

3. Existing Area Characteristics 3.1. Zoning and Land Use

Industrial Drive connects land zoned E-2 (Moderate Intensity Industrial Park) to land zoned E-1 (Urban Employment)

and E-2 in the south portion of the study area. Figure 3 shows the City of Gaithersburg zoning around Industrial

Drive and within the approximate study area. North of I-370 is a mix of zoning: E-2, RP-T and R-A (Low Density

Residential). South of I-370 is largely industrial space and warehouses with additional retail and flex uses. North of I-370 is a single lot warehouse, with the remaining land forested and owned by the City of Gaithersburg. The land

just south of West Deer Park Road that is zoned R-A consists of an elementary school owned by MCPS and a city

owned park owned. The east side of the study area consists of detached single-family homes, while the west side of the study area consists of townhouses (zoned medium-density residential).


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Figure 3: City of Gaithersburg Zoning

3.2. Right of Way and Topography As shown in Figure 4, the general area for a pathway between I-370 and the Muddy Branch stream is a mix of public

and private lands. The private land is a triangular site, immediately to the west of the termination of Industrial Drive.

On either side of the private land is public land that is owned and maintained by the City of Gaithersburg. North of Muddy Branch is public land that is owned by the City of Gaithersburg and Montgomery County Public School

System.

The cul de sac that forms the termination of Industrial Drive has an elevation of about 460 feet above sea level, while

immediately to the north of the cul de sac, there is a steep drop off in elevation down to 430 feet above sea level. The

Muddy Branch stream banks have an elevation of about 400 feet above sea level. As shown in Figure 4, the public land immediately to the northeast of the private site is gently-sloping, while the land immediately to the northwest

has a steeper slope.


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Figure 4: Study Area, with ROW lines (red) and topography

3.3. Existing Trails and Roadways All existing trails in the study area are publicly owned and are north of the Muddy Branch stream. There is a 10’ wide trail along the northern embankment of Muddy Branch, south of the baseball fields. This trail is generally in

good condition. Additionally, there is a 4-ft wide asphalt trail between the baseball fields and the elementary

school. This trail is in need of repaving and has non-ADA compliant cross slopes.

3.4. Existing Lighting Summit Hall Road and West Deer Park Road have standard “cobra” street lighting, while Edgewood Court has

privately-owned pedestrian-scale lighting street side. Industrial Drive, north of I-370, has no roadway lighting.


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4. Additional Data Collected In addition to property/lot lines, topography, and existing trails/bridges, the following data sets were collected to help develop base mapping conditions in CADD to assist in determining where a trail alignment could feasibly be

located.

1. Forest conservation easements. 2. Utilities and easements from WSSC.

3. Water ways (County GIS).

4. Tree Inventory collected in the field.

5. Wetlands delineation.

4.1. Forest Conservation Easements Two existing forest conservation easements were identified within the project study area as depicted on the Existing

Conditions Plan, shown in Figure 5. Forest Conservation easements are shown in hatched green/white markings and abut the private warehouse site. The location and extent of the existing easement was based the recorded Forest

Conservation Easement and Agreement and Plat (L12818 F201 City Plat R-894) obtained from the City of

Gaithersburg and attached herein as Appendix I. During development of conceptual alignments and designs, all efforts have been made to avoid encroachment into the existing forest conservation easements.

4.2. Utility Easements Utility GIS shapefiles were obtained from WSSC for both water and sewer lines. These files were converted to CAD and were overlaid on the existing conditions base map and are shown on Figure 5. Water and sewer lines have a ten-

foot buffer (e.g. twenty-foot wide) easement, where construction may be prohibited – particularly if foundations or

footers are required. The GIS files provided by WSSC do not precisely align with known water and sewer manholes, visible in aerial imagery.


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Figure 5: Forest Conservation Easements and Utility Easements

4.3. Tree Inventory A field assessment, including forest stand delineation, specimen tree location, non-tidal wetland, and waters of the

U.S. (WUS) delineation, was conducted in the study area to characterize and assess the overall habitat and to

specifically identify specimen trees and limits of non-tidal wetlands and WUS. Standard Montgomery County and

Maryland forest conservation sampling procedures were followed when assessing the site. There are 18 acres of woodland within the 42-acre study boundary. The habitat observed is a combination of managed and unmanaged

land, including turf areas, as well as forest areas of a middle to late successional mixed lowland hardwood forest and

a middle successional mixed upland hardwood forest. The small upland forest habitat adjacent to the industrial (AFG Group Inc) parking lot was dominated by various Oak species (Quercus sp.) and a variety of other typical upland

species including Virginia pine (Pinus virginicus), pignut hickory (Carya glabra), American Holly (Ilex opaca), black

cherry (Prunus serotine) and red maple (Acer rubrum). The rest of the forest in the study area consisted of typical lowland hardwood species. The lowland forest was dominated by large tulip poplars (Liriodendron tulipifera) and a

variety of other typical upland species including red maple (Acer rubrum), American holly (Ilex opaca), American

hornbeam (Carpinus caroliniana), American dogwood (Cornus florida) and sweet cherry (Prunus avium). Canopy

cover is approximately 80-100% throughout the entire 18-acre study area. Herbaceous species cover was limited to forest edges and clumped into areas where canopy was thin.


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Locations of specimen trees (> 30” DBH2) and significant trees (>24” DBH) were recorded with a GPS handheld

unit with submeter accuracy. Species, size, and condition were inventoried, locations are shown on the Existing Conditions Plan, Appendix A.

4.4. Water ways The study area includes two stream resources, Waters of the U.S. (WUS), located in the Potomac River

Montgomery County Watershed No. 02140220:

• Muddy Branch, Maryland Department of the Environment Use Class I-P

• A tributary to Muddy Branch, Maryland Department of the Environment Use Class I-P

Centerline location of WUS were field-verified and recorded using a GPS handheld unit with submeter accuracy.

Stream buffers were determined using the steep slope analysis and evaluation as shown on the Existing Conditions

Plan, Appendix A.

4.5. Wetlands delineation Three (3) areas were identified as non-tidal wetlands during the field assessment of the study area. The observed

wetland areas were entirely forested and received ephemeral drainage from seeps within the stream valley and

associated floodplain. Wetland boundaries were delineated and recorded using a GPS handheld unit with submeter accuracy. Wetland buffers were defined per guidance in the City of Gaithersburg Environmental Standards for

Development Regulation.

Wetland soil was indicated by 1” to 3” of undecomposed organic matter, mottles, depleted soils and low-chroma

color. Hydrology indicators included inundation, sulfidic odor, oxidized root channels and water stained leaves.

Vegetation at the time of the study (January 2019) contained wetland indicator obligate, ground cover herbaceous species with some facultative tree species on the edges of the inundated and saturated areas. Trees within the

inundated areas exhibited buttressed trunks.

An inventory from USFWS IPAC list of the study area’s rare, threatened and endangered species was performed. This document is included as Appendix B. No rare, threatened and endangered species were observed on site during

field assessments. An additional inquiry was placed with the Department of Natural Resources (DNR), regarding

presence of any rare, threatened, and endangered species withing the area. Follow-up correspondence from DNR indicated that there are no official State or Federal records for listed plant or animal species within the study area.

The DNR response is included in Appendix B.

Wildlife utilizing the habitat were identified through either direct observation or evidence of previous use including

burrows and scat. Deer and fox are visibly active within the study area. The forest within the bikeway study area

did contain a complex vegetative structure (i.e., variety of canopy, lower and mid story vegetation). A majority of

the forested area contained large mature hardwood trees. One hundred percent of the forest within the study area would be considered “edge” habitat (i.e., forest area within 300 feet of a forest edge). Most of the observed bird use

was limited to a couple of small song birds and some raptor species. Conditions that would indicate forest interior

dwelling species include the presents of forests at least 50 acres (continuing off site) in size as well as most of the forest dominated by pole-sized or larger trees (5 inches or more in diameter). Based on these and other habitat

characteristics listed above, we believe the area supports forest interior dwelling species (FIDS).

Table 1: Observed Plant Species List

2 Diameter at Breast Height.

Common Name Scientific name Stratum Status

Skunk Cabbage Symplocarpus foetidus Ground OBL

Watercress Nasturtium officinale Ground OBL


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Examples of species observed in the wetlands are included in Appendix C.

5. Design Concepts 5.1. Design Assumptions

With an understanding and complete map of existing conditions, several alignments were developed to create a

bikeable facility between the study area limits, defined as Industrial Drive in the South and the intersection of Summit

Hall Road at West Deer Park Road in the North. Prior to development of each alignment, a set of general design criteria were established in conjunction with City staff:

• Design an all-ages facility that is usable for all residents (e.g. a facility that serves those “8 to 80” years old).

• Create a hard surface pathway that is 10’ wide.

o Crushed stone was assumed to not be a viable long-term option.

• Avoid private property to the greatest extent possible.

Broomsedge Andropogon sp. Ground

Christmas fern Polystichum acrostichoides Ground FACU

Sensitive fern Onoclea sensibilis Ground FACW

Blueberry sp. Vaccinium sp. Ground/Shrub

Seedbox Ludwigia alternifolia Ground OBL

Multiflora Rose Rosa multiflora Ground/Shrub FACU

Spicebush Lindera benzoin Shrub FACW

Smilax Smilax sp. Vine

Grape Vitis sp. Vine FACW

Pig nut hickory Carya glabra Canopy FACU

White Ash Fraxinus americana Canopy FACU

Black gum Nyssa sylvatica

Canopy/

Understory FAC

Hornbeam Carpinus caroliniana

Canopy/

Understory FAC

Virginia pine Pinus virginicus Canopy FACU

American Holly Ilex opaca

Canopy/

Understory FAC

Black cherry Prunus serotina

Canopy/

Understory FACU

Sassafras Sassafras albidum

Canopy/

Understory FACU

Black oak Quercus velutina Canopy FACU

Tulip Poplar Liriodendron tulipifera Canopy FACU

Sweet gum Liquidambar styraciflua Canopy FAC

White oak Quercus alba Canopy FACU

Red maple Acer rubrum

Canopy/

Understory FAC

Tree of heaven Ailanthus altissima Canopy FACU

Bradford pear Pyrus calleryana Canopy

Bold=nuisance species * Status source: USACE 2016 Atlantic and Gulf Coastal Plain -National Wetland Plant List, http://wetland-plants.usace.army.mil/nwpl_static/v33/home/home.html

http://en.wikipedia.org/wiki/Sassafras_albidum

http://en.wikipedia.org/wiki/Diospyros_virginiana

http://www.google.com/url?sa=t&rct=j&q=sweet%20gum%20tree&source=web&cd=1&cad=rja&ved=0CCIQFjAA&url=http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FLiquidambar_styraciflua&ei=hGFGUMylGobo9ATtz4CYBQ&usg=AFQjCNFKecsJsjsrg_Wfa4XzsRqpSgTAYg

http://wetland-plants.usace.army.mil/nwpl_static/v33/home/home.html


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• Traditional unprotected bike lanes will not suffice.

• Retain Trees to the greatest extent possible.

• Minimize expensive utility relocation.

• Design for ease of continuing maintenance.

• Minimize impacts on forested land.

• Minimize maintenance of SWM facilities.

• Minimize impacts to wetlands.

• Design for ADA compliance.

5.2. Additional Design Requests Based on intra-agency discussions within the City, several other factors were desired in the construction of the pathway:

• Pathway lighting.

• Wayfinding signage at the project limits.

• Ability to traverse with a large utility truck (e.g., F-250).

• Clear line of site along the path.

5.3. Design Concept Segments Because of the variation in topography, the project study area was divided into three segments, shown in Figure 6:

• Southern Segment, encompassing Industrial Drive from Montgomery County, over I-370, to its northern

terminus in the City of Gaithersburg.

o Only one southern segment alignment is proposed, which entails re-striping Industrial Drive to

provide in-road buffered two-way bike lanes.

• Northern Segment, north of the Muddy Branch stream, to the intersection of West Deer Park Road at Summit Hall Road. This segment constitutes utilizing existing trails as well as expanding existing

sidewalks/paths – all owned and maintained by City of Gaithersburg.

o Two alignments were considered. The first alignment proposes expansion of a narrow existing asphalt path between Morris Park and Summit Hall Elementary for its entire length. The second

alignment proposes expanding the sidewalk along Summit Hall Road, from the Morris Park

Maintenance entrance to West Deer Park Road.

• Central Segment, encompassing the northern terminus of Industrial Drive to and across the Muddy Branch stream. This segment is heavily-wooded, with a portion of it being privately-held and developed with an

industrial/flex use. Because of the complex nature of the terrain, multiple easements, and mix of public and

private ownership, this segment required the most data collection and analysis to develop conceptual

alignments and a preferred alignment. o Three conceptual alignments were developed through this segment: one exclusively on public

property and two others on a mix of public and private property.


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Figure 6: Map of the study area, divided into three segments

The following sections detail the concept development for the three segments listed above.

5.4. Conceptual Designs for the Northern Segment In the Northern Segment of the study area, there are limited means to get from the existing adjacent side path along

the northern bank of the Muddy Branch stream to the intersection of Summit Hall Road at West Deer Park Road.

Potential alignments are shown in Figure 7 and include:

• School Path Alignment: Utilizing the existing asphalt path between Morris Park and Summit Hall

Elementary School, that is proposed to be widened to 10 feet; or

• Maintenance Driveway Alignment: Expanding the existing sidewalk along northbound Summit Hall Road

to 10 feet wide.


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Figure 7: Two conceptual alignments for the Northern Segment

Figure 8 shows the existing path between Morris Park and Summit Hall Elementary. It is approximately 4 feet

wide, with some sections having non-ADA compliant cross slopes (e.g., greater than 2%).

Figure 8: Narrow Path between Morris Park and Summit Hall Elementary, looking east

A proposed typical section for an expanded path from 4 feet to 10 feet wide is shown in Figure 9. Because the path

expansion is to the south toward the baseball fields that are at a lower elevation, addition fill will be required along select sloped areas. Additionally, where the new slope would be sufficiently steep, ADA-compliant handrails are

required. The length for the required handrails is estimated at 150 feet but will need to be confirmed during 30%

design if this alignment is chosen for the northern segment.


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Figure 9: Proposed typical cross section of a widened path between Morris Park and Summit Hall Elementary

The other alignment, follows the existing 10-foot wide path between the baseball field and the Muddy Branch

stream, where it then utilizes the maintenance driveway for Morris Park, before transitioning off-road to a proposed

expansion of the existing sidewalk along northbound Summit Hall Road (Figure 10).

Figure 10: Existing Sidewalk along northbound Summit Hall Road, looking south

The sidewalk will be widened to 10 feet to match the facility’s desired minimum width. As seen in Figure 10, for

this alignment, the fence along the northern property of Summit Hall Elementary will have to be truncated to accommodate a wider sidewalk. Additionally, four existing streetlights along northbound Summit Hall Road will

have to be relocated (e.g. offset 5 feet) in order to install wider sidewalk.


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Both alignments for the northern segment utilize existing pedestrian pathways along City-owned right of way.

Ultimately, if one alignment is chosen for construction and signed as the designated route for pedestrian/bike travel to Industrial Drive, path users may find the other unwidened route equally palatable and will not be precluded from

using it.

5.5. Conceptual Design the Southern Segment The southern segment of the bike facility is expected to be entirely on-road beginning at the terminus of Industrial

Drive (north of I-370) and ending at the City/County line, just south of I-370.3 A quarter-mile south of I-370,

Industrial Drive terminates at Gaither Road, which ultimately provides bikeable access to the King Farm neighborhood in Rockville and to the Shady Grove Metro Station. Industrial Drive is listed as a designated bike

route in the County Bike Master Plan. At the time of this publication, no bike facility planning or design efforts

have commenced for Industrial Drive. The road is generally low volume, serving several industrial/warehouse/flex

sites. North of I-370, Industrial Drive serves only a single warehouse/flex property. Industrial Drive is 50 feet wide, consisting of two 25-foot wide travel lanes, with an additional 5.5 foot wide sidewalk on each side. It is also

occasionally used for on-street parking for large trucks and tractor trailers, as shown in Figure 11.

Figure 11: Industrial Drive looking south from its northern terminus toward the I-370 overpass

Based on the available width and existing uses, Industrial Drive is proposed to be restriped for two 13’ wide travel lanes, a single 10-ft wide northbound parking lane for truck parking, and a buffered two-way curbside bike lane.

The existing and proposed sections of Industrial Drive are shown in Figure 12. This proposed typical section

provides ample capacity for vehicle traffic and parking along Industrial Drive, while providing buffered travel space for cyclists. Additionally, the four foot buffer shown between the parking lane and the two-way cycle track

can be improved with hard or soft vertical installations; examples of common vertical buffers are shown in Figure

13. The ultimate cross-section will depend on coordination between Gaithersburg and Montgomery County.

3 Alternatively, the southern segment could extend further south to Gaither Road, with coordination and buy-in from

Montgomery County. Per discussions with County Planners, it was agreed that Industrial Drive has ample room for on-road

bike facilities.


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Figure 12: Proposed Typical Section for Industrial Drive south of the cul de sac

Figure 13: Examples of commercially available vertical bike buffers

5.6. Conceptual Design for the Central Segment The central segment of the proposed bike facility relates to the alignment south of Muddy Branch, including its crossing, to the Industrial Drive terminus, north of I-370. This segment is largely wooded, with a portion that is

private property and improved with a warehouse/flex building. Additionally, there is a steep grade change between

Industrial Drive and the Muddy Branch stream, as well as wetlands, tributaries, Forest Conservation easements, and utility easements. Three alignments were developed to traverse the wooded central segment; these options are

shown in Figure 14 and are described below:

• Option 1a begins at the terminus of Industrial Drive and traverses westward along the southern perimeter of

the privately-held warehouse property, between the parking lot and I-370, as shown by the green line in

Figure 14. At the western edge of the parking lot, Option 1a follows a switchback trajectory (shown as a blue line in Figure 14), generally following an existing “goat path” toward an existing 4’ wide steel grate

bridge over the Muddy Branch stream.


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• The Option 1b alignment initially follows Option 1a around the southern perimeter of the warehouse

parking lot (green line), but at the western perimeter of the lot, the align travels northward (yellow line)

along existing terrain contours, where it crosses the Muddy Branch stream at a location, opposite the existing path between Morris Park and Summit Hall Elementary.

• Option 2 has an alignment that begins in the south at the termination of Industrial Drive and traverses north

through forested area, between Edgewood Court and the warehouse facility located on private property,

until it reaches the Muddy Branch stream, where a new bridge is proposed, opposite the existing asphalt

path between Morris Park and Summit Hall Elementary.

Of note, the elevation change between Industrial Drive and Muddy Branch consist of a drop of 50 feet. This has an

impact on the way conceptual alignments can be developed, while still maintaining a comfortable and ADA-compliant route. The following three subsections discuss each alignment of the Central segment in greater detail.

Figure 14: Conceptual Routes for Options 1a, 1b, and 2, along the Central Segment of the Bike Facility

5.6.1. Conceptual Design for Option 1a along the Central Segment Referring to Figure 14, Option 1a generally utilizes the southern perimeter of privately-owned land – currently

developed with a warehouse and parking lot – to provide a route for a 10-ft wide asphalt path from the termination of Industrial Drive northward to Muddy Branch. The driveway from the warehouse to the cul de sac termination is

also private, and the asphalt trail is proposed along its southern edge. The asphalt path continues along the southern

perimeter of the property, cutting through small grass berms until it reaches the western edge of the property adjacent to an existing Forest Conservation Easement.

At that point, Option 1a then transitions in a northwest direction, again as a 10-ft wide asphalt path, along land

owned by the City, prior to terminating at a proposed new bridge over the Muddy Branch stream. This portion of the alignment has a “goat path” worn through the woods (see Figure 15) and an elevation drop of about 40 feet

from the western edge of the parking lot to the Muddy Branch Stream banks. Accordingly, this portion of the


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alignment is proposed to have multiple switchbacks to maintain ADA compliance. All the trees between the

switchbacks would be expected to be removed under this option, due to the need to regrade the terrain between them.

Figure 15: Worn trail looking north from warehouse parking lot toward Mudd Branch bridge

Option 1a terminates at the Muddy Branch where a new bridge is proposed to replace the existing steel grate bridge, which is substandard at only 4 feet wide (Figure 16). A new traversable prefabricated-structure truss-bridge is

proposed that is 10 feet wide and is rated for vehicle traffic up to 10,000 lbs. (a typical example of a prefabricated-

structure truss-bridge is shown in Figure 17).

Figure 16: Existing Bridge of Muddy Branch, looking south


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Figure 17: Example of a prefabricated-structure truss bridge

Detailed plan view conceptual drawings for Option 1a are provided in Appendix D.

5.6.2. Conceptual Design for Option 1b along the Central Segment The Option 1b alignment initially comprises a portion of Option 1a, but its route deviates upon reaching the western

edge of the private parking lot (shown in yellow in Figure 18).

Figure 18: Alignment of Option 1b in the Central Segment


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This alignment is proposed as a10-ft wide asphalt path and traverses a lightly-traveled “goat path” (Figure 19) within wooded City property. Within the wooded portion of the study area, Option 1b generally follows the existing contours

of the land to provide a more gradual slope than Option 1a. Because of this longer routing and resulting gradual

slope, less switchbacks are required to maintain ADA-compliance. Option 1b crosses the Muddy Branch stream via

a proposed new truss bridge at a location closer to the baseball fields in Morris Park, opposite the existing 4-ft path that generally separates Morris Park from Summit Hall Elementary. Similar to option 1a, the bridge is proposed to

be 10-ft wide and vehicle-rated up to 10,000 lbs. Detailed plan view conceptual drawings for Option 1b are provided

in Appendix D.

Figure 19: Photo along option 1b, 30 feet south of the Muddy Branch stream, looking north toward Morris Park

5.6.3. Conceptual Design for Option 2 along the Central Segment Option 2 consists of a more direct route between Industrial Drive and the Muddy Branch stream, staying entirely on

publicly-owned land, maintained by the Department of Public Works. See the red alignment in Figure 20.


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Figure 20: Option 2 alignment for the Central Segment

While Option 1a and 1b traverse alignments that have a more gradual slope downward from Industrial Drive to Muddy Branch, the Option 2 alignment begins along a steep elevation change immediately north of Industrial Drive

and then has gentle gradual slope as it heads north toward the Muddy Branch stream. This steep elevation change

north of Industrial Drive requires that the alignment:

• Slopes gradually, by following the existing contours of the terrain; and

• Is raised above the terrain utilizing a structural support system such as retaining walls or elevated boardwalk.

The expense, environmental impact, and maintenance of an extensive retaining wall system precludes its use in this

area, as it would require a wide swath of land to be reconstructed as well as deep structural foundations to support

elevated walls and paths. Accordingly, an elevated boardwalk is proposed to begin at the termination of Industrial Drive and follow the existing contours of the land eastward initially and then northward until it drops about 20 feet

in elevation to a point where it is about four feet above grade. The lateral distance traversed by this portion of the

elevated boardwalk is about 410 feet. The next segment of the elevated boardwalk travels in a northwest direction and is generally level (to offer a respite for users traveling between uphill portions of the facility). After a 300-foot

level section, the boardwalk transitions down to grade near the Edgewood Court cul de sac at maximum 5% slope for

180 feet. The alignment of the boardwalk is proposed to minimize the impacts to nearby wetlands, wetland buffers, and tree roots, as well as reduce the need for culverts to be constructed over existing tributaries that feed into the

Muddy Branch stream.

All elevated portions of the boardwalk must be constructed with hand rails as shown in Figure 21. Note that boardwalk construction is based on raised (helical) concrete piers, with support beams anchored on top, to support

the lateral joists and decking. This construction method minimized impact to tree roots and allows for construction

of tributaries.


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Figure 21: Example of boardwalk over wetlands in a stream valley (Patuxent River Trail, Howard County, MD)

As the boardwalk reaches grade near Edgewood Court, the alignment follows existing public right of way that

parallels Edgewood Court, but is offset 30 feet ± from the road edge. Within this portion, the alignment is proposed as an asphalt path until it reaches Muddy Branch, where a new crossing is proposed via a prefabricated truss bridge.

Proposed grading and alignment of the asphalt section is sited to avoid and minimize impacts to specimen trees and

non-tidal wetlands and their buffers. More detailed plan view conceptual drawings for Option 2 are provided in Appendix E.

6. Construction and Maintenance Costs for each Option Construction estimates were developed for each alignment, within each segment, of the proposed bike facility in

order to develop a range of costs:

• Northern Segment

o Alignment adjacent to Summit Hall Elementary o Alignment along Morris Park Maintenance Yard

• Southern Segment

o Re-striping Industrial Drive

• Central Segment

o Option 1a alignment o Option 1b alignment

o Option 2 alignment

Factors involved in the cost of each alignment include:

• The cost of an asphalt path or boardwalk.

• A new ADA-compliant and wider bridge over Muddy Branch.


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• Widening of either existing pathway or existing.

• Retaining walls and fencing.

• Hand rails.

• SWM facilities.

• Culverts over existing tributaries.

• Re-grading.

• New and relocated lighting.

• Wayfinding signage.

• ADA-complaint pedestrian/bike ramps.

• Signage and pavement markings.

6.1. Northern Segment Construction Cost There are two alignments for continuing the path northward from Morris Park to the intersection of Summit Hall Road at West Deer Park Road:

• Widening the existing pathway between Morris Park and Summit Hall Elementary School

• Widening the sidewalk along northbound Summit Hall Road from the park maintenance entrance to West

Deer Park Road.

Widening the existing pathway between Morris Park and Summit Hall Elementary School requires regrading, new

handrails, as well as additional asphalt and gravel base. The cost of this construction is estimated to be $36,000.

Widening the sidewalk along northbound Summit Hall Road from the park maintenance entrance to West Deer

Park Road requires regrading, streetlight relocation, relocating a small section of fencing near the school, as well as

additional concrete and gravel base. The construction cost estimate for this work is $54,000.

Appendix F shows the approximate quantities and unit costs for each of these two alignments.

6.2. Southern Segment Construction Cost Assuming that no resurfacing costs are associated with the re-striping of Industrial Lane, construction costs involve

only new signing and pavement markings (e.g. re-striping and bike lane symbols), as well as eradication of exiting

pavement markings. Based on the ½ miles distance between the northern terminus of Industrial Drive and its

intersection with Gaither Road in the south, the approximate cost of re-striping for two-way bike lanes is approximately $20,000 for painted line striping or $35,000 if thermoplastic is used in lieu of paint. The advantage

of thermoplastic over paint is that it will require less continuing maintenance; however the longevity of both paint

and thermoplastic depend greatly on the quality of the road surface to which they are applied.

6.3. Central Segment Construction Cost The primary driver of the construction cost for the preferred bike facility design relates to the preferred alignment

through the central segment of the study area, due to elevation changes, need for ADA compliance, presence of wetlands, tributaries, easements, and the need for a new bridge across the Muddy Branch stream.

Options 1a and 1b have similar construction methods, with the former requiring additional tree removal and clearing/grubbing due to the proximity of multiple switchbacks. Option 2 has much less paving involved but

utilizes elevated marine-treated boardwalks. Overall, Option 2 is about 2/3rd as long, compared with Options 1a or

1b, within the central segment of the bike facility.

Options 1a and 1b are comprised primarily of a 10-foot wide asphalt path. To ensure limited vehicle operation on

the path, it is proposed to be constructed with a 6” stone sub-base, 4” asphalt base course, and 2” asphalt surface

course. Generally, the sub-base and base courses are laid wider than the asphalt top course. Option 1a has a


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steeper slope along its route and therefore requires several switchbacks for ADA compliance. The final design of

the switchback will depend on the design-vehicle type that will be used on the path for maintenance purposes. For example, a gator will have a narrower and tighter turn path than a light-duty pickup truck. Option 1a will require

more deforestation, compared to Option 1b, in order to accommodate these additional switchbacks; however, the

areas between switchbacks can potentially be utilized for SWM facilities.

Option 2 has a much shorter asphalt path section and will need fewer SWM facilities to treat run-off. In general,

Option 2 is a shorter route, but requires elevated boardwalk sections to accommodate the steep drop in grade from

the Industrial Drive cul de sac down to the flat city-owned land adjacent to Edgewood Court. The boardwalks are proposed to be constructed with marine retention treated lumber, using 3x10 framing and 2x10 decking. See Figure

22 for an example of boardwalk construction through a stream valley. This construction is rated for vehicular use

up to 10,000 pounds. (e.g. gators and light-duty trucks). The elevated portions of the boardwalk is about 400 feet long and will require deep foundations and larger supports than that portions that are closer to grade. These

elevated portions will cost substantially more on a per linear foot basis. For maintenance, only gators are

recommended to be allowed on the elevated portion of the boardwalk; designing it to accommodate light-duty

trucks with larger turning paths will substantially increase the width and the cost of the elevated section.

Figure 22: Standard detail for Boardwalk Support (source: Montgomery Parks)

Finally, culverts are proposed along the asphalt portion of Option 2, where it crosses existing tributaries.

Option 1a and Option 1b thru the Central segment of the study area have an estimated construction cost of

$425,000, and $410,000, respectively. Note, that this does not include costs associated with acquiring ROW or

public easements on the portion of the alignments that are on private property.

Option 2, while shorter in length, is estimated to cost about $680,000. The additional cost is related to higher cost

per liner foot of an elevated boardwalk with handrails, relative to the cost of an asphalt path. Appendix F shows a breakdown of the construction cost for each option.

6.4. Construction Cost Summary for the Bike Facility Because there are multiple options for the northern and central segments of the proposed bike facility, there is a large range in total construction costs. Table 2 lists the range of costs for each alignment within each segment.


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Table 2: Range of Construction Costs for all Alignments

Segment Alignment Cost

Northern Path Expansion adjacent to Summit Hall Elementary $36,000

Sidewalk Expansion along Northbound Summit Hall Road $54,000

Central Option 1a, Asphalt path along mix of private/public property $425,000

Option 1b, Asphalt path along mix of private/public property $410,000

Option 2, asphalt path & boardwalk along public property $680,000

Southern Re-stripe Industrial Drive for two-way buffered bike lanes $20,000

Based on the available alignments for each segment, the construction cost ranges from $466,000 to $754,000, not

including ROW acquisition costs related to Options 1a and 1b.

6.5. Maintenance and Final Design Cost

Final Design costs for the bike facility through all three segments, - northern, southern, and central - of the study

rare expected to be about $250,000 with topographic survey, any borings needed for stormwater facility design, as

well and stormwater management facility approval and permitting. This design cost assumes asphalt construction. If an elevated boardwalk is utilized for all or a portion of the alignment thru the central segment, then the Final

Design costs are expected to be about $300,000, with the additional costs related to the structural engineering and

design for the elevated portions of the boardwalk.

Estimated annual maintenance cost for all alignments that involve asphalt paths is expected to be about $1,500 per

year. This maintenance covers annual evaluation of facility for signs of degradation; leaf/vegetation growth removal; snow removal; and repairs for any cracks or potholes. Alignments that include a boardwalk in lieu of an

asphalt path require additional maintenance related to:

• Replace/repair boards from occasional tree damage.

• Replace wood on sections over wetlands that may rot.

• Pressure washing once per year to address spot algae removal.

o Algae is more prevalent on boardwalk areas that are surrounded by dense forest.

Accordingly, any alignment that involves utilizing boardwalk in lieu of an asphalt path will increase the annual

maintenance costs by an additional $500 per year.

7. Community Input Typically for the planning stage of an infrastructure project of this type, an in-person public meeting is held where concepts are discussed with a group of interested or affected residents. Concepts are provided on maps and input is

directly solicited. However, at the time this phase of the feasibility study was ongoing, County guidelines

prohibited large gatherings, for health reasons related to Covid-19 virus. In lieu of an in-person meeting, a virtual

survey was developed, that provided general information on Options 1a, 1b, and 2, and with their alignments on a map. They online survey solicited opinions on alignment preference as well as other general information related to

the project. The survey was open from approximately May 12th thru May 31st and was advertised on the City

website, social media, and the City’s project web page. The survey questions asked were:

• Do you bike recreationally now?

• Do you walk recreationally now?

• Will you use this facility for? (check all that apply): o Recreation

o Retail/business trips

o Commuting to Metro or other bus stops.

o If you would not use the path, are there any amenities that the City can provide in its design that would cause you to use it?


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• Do you have comments or concerns about this path that you would like to provide to the City?

• Do you have a preferred option and why?

• What is your Zip Code?

Finally, the survey was anonymous, but optionally requested addresses and emails, if respondents desired to share them.

Sixty-two respondents responded, mostly from zip code

20877, which encompasses the study area. Common amenities that respondents wanted to see in the facility

include:

• Water fountain & bathrooms in park,

• Distance signs

• Avoid Edgewood Court

• Keep it a short facility

• Provide a wide path

• Lighting

• Keep path maintained

The remaining survey resulted are summarized in Figure 24,

but generally:

• Most respondents bike recreationally, while almost all walked recreationally

• Of the 62 respondents:

o 54 (87%) would use this facility recreationally o 25 (40%) would use this facility for retail/business trips

o 14 (23%) would use this facility to bike/walk to the Metro or bus stops.

• While 14% of respondents would choose either option, there was a strong preference (57%) for Option 2.

Option 1a and option 1b was preferred by 10% and 19%, respectively.

Figure 23: Zip code of survey respondents


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Figure 24: Public survey results

Complete survey results, including all comments are provided in Appendix G.

7.1. Intra-agency Input During the online survey comment period, the following City input was provided

• From select City Council: o Concerns about trail placement north of Muddy Branch being close to school property. Suggested

alignment was to utilize the park maintenance access road and widen sidewalk along Summit Hall

Road.

• From Planning:

o There are two forest conservation easements and a floodplain on the private property portion of the wooded area. Easements can be disturbed and paths can be located with a floodplain, but any

structures (e.g. retaining walls) will require a variance granted by the Board of Appeals.

o The City’s internal policy is that forest disturbances are replaced on a 1:1 level, per Forest Conservation memo Forest Conservation Plan Process for Capital Improvement Projects,

December 13, 2016

o Avoid wetlands. The first 25’ buffer around wetlands is state-controlled and the State may be resistant to asphalt paths in the buffer.

8. Recommended Option and Design Details To compare all of the alignments, the following metrics were evaluated:

• ROW Impacts

• Increase in Impervious Area

• Forest Stand Impacts and Tree Removal


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• Wetland and Wetland Buffer Impacts

• Utility and Forest Conservation Easement Impacts

• Tributary or WUS crossings

• Public Preference (central segment only)

• Construction Cost

A summary of these impacts is shown in Table 3. Table 3: Comparison of Alignment Impacts

With regard to the southern segment of the study area, only one alignment is proffered – restriping Industrial Drive

for a two-way bike lane. While the final design may have subtle changes to the proposed typical section, it will

likely be similar in cost and impact to the one described herein. The final design ad typical section will ultimately

be determined in coordination with Montgomery County Planning and MCDOT.

ROW Impacts

Increase in

Impervious

Area

Tree Removal

Wetland and

Wetland Buffer

Impacts

Easement

Impacts

Tributary or

WUS crossing

Public

Preference

(central

segment only)

Construction

Cost

Path Expansion

adjacent to Summit

Hall Elementary

None. All Public

Land3400 SF None N/A None N/A N/A $36,000

Sidewalk Expansion

along Northbound

Summit Hall Road

Summit Hall sidewalk

expansion has a 600

SF encroachment on

MCPS property.

Easement Required.

4500 SF None N/A N/A

N/A. Council

preferred this

alignment over

school path

expansion.

$54,000

Option 1a, Asphalt

path along mix of

private/ public

property

Encroaches on 13000

square feet of private

property. Public

easement required

27,000 SF

Impacts to Forest Stand A-1 and

B-1 (~ 1.5 acres of wooded area

total) including 4 trees impacted

with a Diameter at breast height

(Dbh) of 24" or greater. All 1.5

acres will need be to clear cut

for switchbacks. This area can

be partially replanted in

coordination with SWM facilities

located between switchbacks.

None

Crosses 1

WSSC

easement.

Crosses 1

forest

conservation

easement

Muddy Branch

only

Acceptable

Option$425,000

Option 1b, Asphalt

path along mix of

private/public property

Encroaches on 13000

square feet of private

property. Public

easement required

26,000 SF

Impacts to Forest Stand A-1 and

B-1 (~0.5 acres wooded area

total) including 2 trees impacted

with a Diameter at breast height

(Dbh) of 24" or greater. Tree

impacts can be reduced by

raising path above grade and

applying tree root barrier liner.

Also, path alignment be modified

slightly to avoid root zones.

None

Crosses 1

WSSC

easement.

Crosses 1

forest

conservation

easement

Muddy Branch

only

Acceptable

Option$410,000

Option 2, asphalt path

& boardwalk along

public property

None. All Public

Land10,000 SF

No impacts to any Forest Stands,

but 5 trees impacted with a

Diameter at breast height (Dbh)

of 24" or greater. Boardwalk

construction does not result in

tree root impacts, however,

adjoining asphalt path does. Tree

impacts can be reduced by

raising path above grade and

applying tree root barrier liner.

Also, path alignment be modified

slightly to avoid root zones.

None

Crosses 1

WSSC

easement

5 crossings

plus Muddy

Branch

Preferred

Option$680,000

Southern

Re-stripe Industrial

Drive for two-way

buffered bike lanes

None. All Public

LandN/A N/A N/A N/A N/A N/A $20,000

Northern

Central

Metric Evaluated

Segment Alignment


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With regard to the northern segment of the study area, two alignments are proposed with generally similar impacts and costs. City Council weighed in during the public comment period with a preference for the alignment that

expands the sidewalk along northbound Summit Hall Road. At this time, both options should be explored further

during 30% design to determine final impacts and costs, as well as to solicit opinions on public preference.

Alignments through the central segment of the study area have the most environmental impacts and largest

contribution to the overall project cost. The following table summarizes the benefits and disadvantages of each

alignment through the Central segment of the study area. Table 4: Comparison of each alignment within the Central Segment of the Study Area

Option Description Advantages Disadvantages

1a Asphalt path on private

and public property • Utilizes most heavily-used worn

path through woods

• Generally follows existing terrain

contours

• Crosses Muddy Branch where an

existing bridge and abutment are

located

• Requires the most tree removal and

woodland disturbance.

• Least Preferred Option in public

survey

• Partial construction on private

property. Property easement or

acquisition required

• Partial construction forest

conservation easement

• Requires multiple switchbacks to

achieve ADA compliance

• Staging will be difficult along

sloped portions of alignment

1b Asphalt path on private

and public property • Utilizes an existing worn path

through woods

• Expected to be least expensive

option

• Easiest to design for large truck

accessibility

• Generally follows existing terrain

contours

• Partial construction on private

property. Property easement or

acquisition required

• Partial construction forest

conservation easement

• Highest SWM mitigation needs

• Most circuitous routing.

• Staging will be difficult along

sloped portions of alignment

2 Boardwalk and asphalt

path on public property • Least impactful to tree roots,

drainage patterns, and soil compaction.

• Minimize or eliminate the need

for grading of steep slopes that

would require extensive tree

removal and permanent impacts

to wetland and waters of the U.S.

• Reduces the amount of new

impervious surface

• Least amount of stormwater to

treat.

• No easements or property acquisition is required.

• Shortest alignment

• Most preferred option in public

survey

• Staging and access for construction

will be challenging along the steep sections adjacent to Industrial

Drive and in environmentally

sensitive areas within the

floodplain.

• Potentially increased maintenance

for the boardwalk structure

• Costliest to construct

Based on an analysis of the benefits and disadvantages of each option, and in consultation with City Staff, the recommended alignment through the Central segment of the study area is Option 2. While it is the most expensive,


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this option has the least impervious surface are to treat and is the least impact to existing tree stands. Also, the

option 2 alignment does not impact existing forest conservation easements. Additionally, because the boardwalk is constructed on piers, its layout can be designed and tweaked to minimize impacts to existing tree root structures.

Finally, the alignment for Option 2 is entirely in the public right of way, so no public easements or property takes

are required. Therefore, the Option 2 alignment is recommended to proceed into the next phase of design.

Based on this recommendation, Option 2 was developed conceptually in more detail avoiding the known location of

utility easements, trees, wetland, and wetland buffers. The design also was advanced while adhering to Federal

ADA guidelines for trails and Montgomery County trail design guidelines. Montgomery County provides the following guidance on trail design with stream valleys4:

• Alignment should avoid or minimize impacts to sensitive natural resources, such as floodplains, stream

buffers, steep slopes, highly erodible soils, wetlands and rare, threatened and endangered (RTE) habitat.

• Alignment should also avoid and/or minimize impacts to cultural, historical and archeological resources.

o To reduce disturbance during trail construction/enhancement, follow existing land contours and reduce the use of grading to the extent possible.

o Distance between the trail and stream is typically 50 to 100 feet to avoid construction in the 100-

year floodplain where feasible.

• To improve connectivity and access, consider providing bridges or trail spurs to connect to nearby bicycle

corridors, trails and neighborhood streets.

8.1. Design Details to be explored during Final Design

Notable design elements to be carried over into 30% and Final Design include:

• Stormwater Facility Design

• Boardwalk Slope

• Lighting

• Wayfinding

These items are discussed further in the following subsections.

8.1.1. Stormwater Facility Design With the bike facility predominantly located in wooded areas within a stream valley, there are limited options for

managing stormwater runoff created by new impervious surface. Option 2 through the central segment of the study

area has less impervious surface than Options 1a or 1b, and therefore lower stormwater management needs.

Per internal discussions with City of Gaithersburg staff, mitigating stormwater runoff will utilize non-rooftop

disconnect to the greatest extent possible to reduce overall impacts of the project, with side swales and bioretention or rain gardens installed only as needed to meet the Maryland Department of Environment (MDE) and City of

Gaithersburg Stormwater regulations. Per the MDE Stormwater Design Manual:

“Non-rooftop disconnection involves directing flow from impervious surfaces onto vegetated areas where it

can soak into or filter over the ground. This disconnects these surfaces from the storm drain system,

reducing both runoff volume and pollutants delivered to receiving waters.”5

The viability of applying non-rooftop disconnect depends on sufficient permeable space to accommodate the

minimum flow path length downstream of the impervious path; maximum of 5% downgrade slope, but preferably

4 Bicycle Facility Design Toolkit, Montgomery County Department of Planning, 2017. 5 MDE Stormwater Design Manual, Chapter 5. Revised May 2009


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less; undisturbed sandy, non-clayey soils; and a small enough impervious area to prevent flow concentration onto

permeable treatment areas. An example of non-rooftop disconnect operation is shown in Figure 25.

Figure 25: Example of non-rooftop disconnect (source MDE Stormwater Guidelines)

If the non-rooftop disconnect is not sufficient to treat the drainage area, shallow-depth side swale, similar to the one

shown in Figure 26, or a rain garden, as shown in Figure 27, will be utilized. A grassed side swale is typically a

parallel channel that conveys runoff, providing water quality treatment and flow attenuation of runoff. Rain gardens are shallow and excavated elements that temporarily hold runoff, allowing it to slowly filter through to a

soil bed. A rain garden consists of surface planting with shrubs, grasses, and flowers, a surface mulch layer, and a

planting media layer.

Figure 26: Example typical section of a shallow depth side swale


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Figure 27: Rain garden typical section (source: Montgomery County DPS)

Preliminary SWM requirement calculations for all conceptual design options are summarized briefly in Table 5.

Option 2 in the Central segment has several locations along its alignment that would provide space for grass swales

or rain gardens.

Note, that pervious pavement was discussed with the City as a potential option, but was dismissed due to expected

maintenance requirements (e.g., porous pavement located in a heavily wooded area will be expected to clog often

due to leaf, dirt, and tree debris). Table 5: Approximate SWM requirements calculation for the proposed design options

Design

Option

Impervious Area Require

Treatment (IART)

Required Water

Quality Volume (WQv)

Required

ESDv Remarks

1-A 0.64 Acres 2207 cf 4856 cf 2 outfalls / drainage areas

1-B 0.69 Acres 2379 cf 5235 cf 3 outfalls / drainage areas

2 0.32 Acres 1103 cf 2428 cf 2 outfalls / drainage areas

8.1.2. Boardwalk Slope and Design Specific ADA guidelines6 are availabe for trail design. Adhering to these guidelines, the boardwalk portion of

Option 2 was conceptually designed with the following criteria:

• Begin with a large level platform at the termination of Industrial Drive where the elevation is 456 feet above sea level.

• After a 20’ level landing, proceed at a slope of 1:12 for 200 feet, followed by an additional level landing

that is ten feet in length.

o This portion of the boardwalk is raised well above-grade, but laterally follows existing contour

lines

• The next boardwalk segment is followed by a more gradual slope of 1:50 for 200 feet.

• This section is followed by a level boardwalks segment for 300 feet, over WUS.

• Finally, the last boardwalk segment that ties into the asphalt portion of Option2, has a slope of 1:20 for 180

feet.

The boardwalk is generally sited to avoid wetlands, 25’ wetland buffers, and large trees.

6 https://www.access-board.gov/guidelines-and-standards/recreation-facilities/outdoor-developed-areas/background/committee-

report/trails

https://www.access-board.gov/guidelines-and-standards/recreation-facilities/outdoor-developed-areas/background/committee-report/trails

https://www.access-board.gov/guidelines-and-standards/recreation-facilities/outdoor-developed-areas/background/committee-report/trails


35 | P a g e

8.1.3. Lighting Four (4) new locations for pedestrian scale, downward facing lighting are proposed. This lighting type will minimize lighting intrusion into adjacent housing, while still providing periodic lighting throughout the path.

Generally, this lighting is proposed:

• Where the boardwalks starts at the termination of Industrial Drive (overhead “cobra” streetlight)

• Two locations along the boardwalk – approximately 300 feet apart adjacent to (Pedestrian-scale)

• One location along the asphalt path, between Muddy Branch and the boardwalk portion of the alignment

(Pedestrian-scale)

Final lighting type and location is subject to City approval.

8.1.4. Wayfinding Wayfinding signage is recommended at three locations. The wayfinding signage should indicate a common

destination and a distance. The three locations are

• Beginning of the boardwalk at Industrial Drive

o “Summit Hall Road ½ Mile”

• Summit Hall Road at Morris Park Maintenance Driveway o Industrial Drive ½ Mile

• At the proposed truss bridge over Muddy Branch

o Summit Hall Road ¼ Mile →

o Industrial Drive ¼ Mile

The recommended design and concept-level drawings (e.g. 10% design) for Option 2 through the central segment,

as well as for the two alignments in the northern segment, are shown in Appendix H.

8.1.5. Additional Design Notes Option 2 through the central segment of the study area is located approximately 30 feet from Edgewood Court at

grade level. Typically, a connecting route from Edgewood Court to the path would be proposed to provide

accessibility from the adjacent neighborhood. However, per the annexation agreement X-136 (incorporated herein as Appendix J), a connection between Edgewood Court and Industrial Drive is prohibited.

9. Implementation and Funding Strategies

Funding for projects can often be an obstacle to implementation. In addition to using local funds, there are several

state/federal grant programs that offer monetary support for implementing the recommended bicycle facilities in this study. The following funding sources have been identified as applicable and potential grant program.

Transportation Alternatives Program (TAP). This program is administered and supported by the Maryland State Highway Administration, with reimbursement from the Federal Highway Administration, for the purpose of funding

projects that enhance the cultural, aesthetic, historic, and environmental aspects of the State’s intermodal

transportation system. The program is set up to sub-allocate fifty percent of the funding directly to local Metropolitan Planning Organizations who are the responsible reviewers of proposed projects within their jurisdiction.

Recommendations under this study would be eligible as they meet the requirements of 1) related to surface

transportation; and 2) meet at least one of the nine qualifying TAP categories. Project sponsors are responsible for

design, management, construction, implementation, and permits as well as a minimum of 20% of all project costs.

Maryland Bikeways Program. Supported and administered by the Maryland Department of Transportation, the goal

of the program is to fill in the gaps in Maryland’s bike network to support bikeshare programs. An eligible project meets one of the following criteria: 1) located substantially within the Priority Funding Area (PFA) and/or located


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within three miles of a rail transit station or major bus transit hub, 2) provide or enhance bicycle access along any

gap identified in the Statewide Trails Plan “A Greener Way to Go”, and/or 3) identified as a transportation priority in a County’s most recent annual priority letter submitted to MDOT. The recommendations under this study will meet

the first criterion as the study area is located within a PFA. The local match requirements are a) zero percent for

priority minor retrofit, b) twenty percent for other priority projects, and c) fifty percent for non-priority projects. The

match may include cash or in-kind services contributing to the project such as expenditures up to twenty-four months prior to a Bikeways project award.

Recreational Trails Program. Administered by the State Highway Administration and supported by an 80/20 federal to local match, this program funds community based, motorized and non-motorized recreational trail projects. The

trails can be for pedestrian and bicycling paths as well as for specific uses such as in-line skating, cross-country

skiing, equestrian use, and four-wheel driving. The program funds not only new construction of trails, but maintenance and restoration of existing trails, purchase or lease of trail construction equipment, acquisition of

easements or property for trails, and implementation of interpretive/education programs to promote intrinsic qualities,

safety, and environmental protection. The matching funds must be committed in the local jurisdiction’s budget and

awards may not exceed $40,000 for new construction and $30,000 for other projects. Preferred programs to be funded include the following characteristics: connect communities with natural/cultural areas or tourism areas (e.g. Scenic

Byways, Heritage Areas, Canal Towns); have broad-based community support; complete a missing link in the State

Trails Plan; or link or complete existing trails.

Safe Routes to Schools. Administered by the State Highway Administration and supported by an 80/20 federal to

local match, this program funds infrastructure and non-infrastructure projects that support safe and sustainable routes

for K-8 aged children to walk, roll, or bicycle to school. Projects categorized as safe routes to school must be requested through the larger Transportation Alternatives Program. Eligible project types that overlap with the recommendations

under this study include traffic calming and speed reduction improvements, bike/pedestrian crossing improvements,

and bicycle parking. This program would be applicable; Summit Hall Elementary Schools located within the study area and would allow the City to qualify for Safe Routes to School funding.

MWCOG Transportation Land Use Connections (TLC) Grants. As a member of MWCOG, Gaithersburg can apply for Planning and Design grants to fund studies or designs for planned projects. The TLC Program will provide

consultant assistance, valued between $30,000 - $60,000 for planning projects and up to $80,000 for design or

preliminary engineering projects, for projects that promote mixed-use, walkable communities and support a variety

of transportation alternatives7.

10. Summary and Next Steps

Existing conditions base mapping was the first required step in order to first develop potential alignments for a

pedestrian and bike-accessible path for crossing City-owned parkland north of I-370 and across Muddy Branch to

Summit Hall Road. Base mapping was developed from existing City/County GIS layers, 2’ contour lines, Utility files from WSSC, wetland GIS information, Forest Conservation plats, tree inventory, and field visits. From the base

mapping, the bike facility project was divided into three segments – a northern segment, a central segment, and a

southern segment. The northern segment is north of the Muddy Branch Stream, and the Southern segment is south of the Industrial Drive cul de sac. The Central segment is between Industrial Drive and the Muddy Branch stream,

included a crossing over it. For the Northern segment, two options were developed using existing pedestrian

pathways. For the Southern segment, a single proposed typical section was developed for re-striping Industrial Drive; further coordination with Montgomery County will be needed as this project advances to the next phase of design.

For the Central segment, three alignments were developed:

• Option 1a on private and public property that generally followed the informal worn path thru the wooded

area and crossed Muddy Branch where this is an existing small footbridge.

7 The current feasibility study and 10% Design was funded through a TLC grant.


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• Option 1b, which is similar to Option 1a, but with a longer alignment and different crossing location of

Muddy Branch – further east, close the baseball fields.

• Option 2, entirely on public land, that utilizes a raised boardwalk in conjunction with an asphalt path through

the wooded area before crossing Muddy Branch at the same location as Option 1b.

The Central segment has the most difficult construction barriers, will require the most design effort, and will be the

costliest to construct and permit. Design considerations for the Central segment included:

• Design an all-ages facility that is usable for all residents (e.g. a facility that serves those “8 to 80” years old)

• Create a hard surface pathway that is 10’ wide

• Avoid private property to the greatest extent possible

• Traditional unprotected bike lanes will not suffice

• Retain Trees to the greatest extent possible

• Minimize expensive utility relocation

• Design for ease of continuing maintenance

• Minimize impacts on forested land

• Minimize maintenance of SWM facilities

• Minimize impacts to wetlands

• Design for ADA compliance

Based on these criteria, the three alignments were analyzed for the Central segment to determine which is the most

viable, with benefits and disadvantages weighed for each alignment. Additionally, public opinion on these alignments

were solicited via an online survey, where the Option 2 alignment was the most preferred, with several respondents commenting on its more direct routing and potential for neighborhood connectivity. Finally, construction costs and

yearly maintenance costs were developed for each option. The Option 2 alignment was developed further into 10%

design drawings, shown in Appendix H.

Based on the available alignments for each segment, the construction cost ranges from $466,000 to $754,000 and

depend on whether asphalt or raised boardwalk is the primary construction material thru the Central segment of the study area. Final Design costs are expected to be between $250,000 and $300,000 including survey, any needed

borings, and permitting. Estimated annual maintenance costs for Options 1a and 1b are expected to be about $1,000

per year, while option 2 maintenance costs are expected to be about $1500 per year.

Based on an impact analysis, the following alignments are recommended for each segment of the study area:

• For the Northern Segment: Advance both alignments into 30% design with engineering cost estimates, and

solicit City Council and public input into each

• For the Southern Segment: Coordinate with Montgomery Planning and MCDOT on the proposed typical

section for the entirety of Industrial Drive.

• For the Central Segment: Proceed with the Option 2 alignment to 30% Design

10.1. Next Steps

If the Mayor and City Council concurs with Staff’s recommendation, the next phase of design will be for 30%, to include Site Plan approval prior to obtaining all permits, and then finally 100% design and construction documents

for bidding. To continue this project, the 30% design phase should provide the following:

• A lighting analysis is recommended to determine where there is deficient lighting level and where

recommended lighting should be placed. A photometric plan will be required during site plan submission

• Approved Stormwater plan. A preliminary evaluation of the stormwater needs showed that runoff from

Option 2 can be mitigated with only two SWM features. The City will be required to consult with

Montgomery County Department of Permitting Services (DPS) on SWM facility type and design during

30% design


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o This evaluation and plan approval may require soil borings, depending on the facility type chosen.

• Formal topographic survey and underground utility designation.

• Structural evaluation of the wooded area to determine what type of footing is needed based on the height of

the boardwalk above grade.

• Formal wayfinding signing plan

• Refined engineering cost estimate for construction.

Finally, environmental permitting needs to be obtained after Site Plan approval, include:

• Natural Resource Inventory Plan/ Forest Stand Delineation Plan; the reviewing agency is the City of

Gaithersburg Planning and Code Administration.

• Field assessment and inventory of environmental features (this is completed).

• Preliminary /Final Forest Conservation Plan (FCP), if needed, reviewing agency City of Gaithersburg Planning and Code Administration and Planning Commission. The FCP can be approved in conjunction

with Site Plan approval.

o Options for mitigation plantings will need to be identified and may include plantings at Morris Park

or Summit Hall Elementary School and/or an offsite location within the same watershed in accordance with priority locations identified in the City of Gaithersburg Tree Manual and

Maryland State Forest Conservation Manual. Alternatively, fee in lieu may be considered.

• Wetland and Waters of the U.S. Impact Plates and Permit, reviewing agency Maryland Department of the

Environment8.

• Permanent impacts to Waters of the U.S. requires review and approval by Army Corps of Engineers.

• Floodplain Study and Hydraulic Analysis; reviewing agency Maryland Department of the Environment. o Required for construction or replacement of a bridge structure within the floodplain of Muddy

Branch.

During the Final Design stage, a subsequent step will be to secure funding for construction. Several Federal and State grants are available for both design services and for construction of bike facilities.

Because the overall construction costs are large and likely to exceed any singular State/Federal grant, building the bike facility in phases is recommended. Logical phases would include: 1) the path south of Muddy Branch, including

a bike/pedestrian bridge over it, and; 2) the segment north of Muddy Branch to the intersection of Summit Hall Road

at West Deer Park Road; and 3) re-striping of Industrial Drive, south to Gaither Road (with approval and consent from Montgomery County), in lieu of its designation as a preferred bike route in the County’s Bike Master Plan.

8 Wetlands are regulated in accordance with State (Code of Maryland Regulations {COMAR} 08.05.04) and Federal Nontidal

Wetlands Regulations (Secs. 401 & 404 of the Clean Water Act).

Industrial Drive Bike Connection Feasibility Study and ...

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