CHAPTER 18 – NEIGHBORHOOD TRAFFIC SAFETY

TABLE OF CONTENTS

Section Title Page

18.1 General ....................................................................................................................... 18-1

18.1.1 Intended Use...............................................................................................................................18-1

18.1.2 Traffic Calming for New Street Design ...................................................................................18-1

18.1.3 Roundabouts and Mini Roundabouts ......................................................................................18-1

18.2 Traffic Safety Problems............................................................................................. 18-1

18.2.1 Speeding......................................................................................................................................18-1

18.2.2 Measuring Speed of Roadway ..................................................................................................18-2

18.2.3 Intrusion (Cut-Through Traffic) ..............................................................................................18-2

18.2.4 Pedestrian Safety .......................................................................................................................18-2

18.3 Traffic Calming Design Criteria ................................................................................ 18-2

18.3.1 Speed Limit Signs ......................................................................................................................18-2

18.3.2 Speed Humps..............................................................................................................................18-2

18.3.3 Dips .............................................................................................................................................18-2

18.3.4 Mini Roundabouts .....................................................................................................................18-3

18.3.5 Neckdowns..................................................................................................................................18-3

18.3.6 Traversable Barriers .................................................................................................................18-3

18.3.7 Deviations (Chicanes) ................................................................................................................18-3

18.3.8 Raised Intersections...................................................................................................................18-3

18.3.9 Neighborhood Identification Island .........................................................................................18-3

18.3.10 Drop Off Zone for Schools ........................................................................................................18-3

18.3.11 Intersection Chokers .................................................................................................................18-3

18.3.12 Turn Prohibitors........................................................................................................................18-3

18.3.13 Semi-Diverters............................................................................................................................18-3

18.3.14 Lane Eliminating Choker – Loveland (GMA and city limits) ...............................................18-3

18.3.15 Diagonal Diverters .....................................................................................................................18-3

18.3.16 Realigned Intersections .............................................................................................................18-4

Larimer County Urban Area Street Standards – Repealed and Reenacted April 1, 2007 Page 18-i Adopted by Larimer County, City of Loveland, City of Fort Collins

LIST OF TABLES

This Chapter Does Not Contain Tables

LIST OF FIGURES

Figures are Located at End of Chapter

Figure 18-1 Neckdowns

Figure 18-2 Traversable Barriers

Figure 18-3 Deviations (Chicanes)

Figure 18-4 Raised Intersections

Figure 18-5 Neighborhood Identification Island

Figure 18-6 Drop Off Zone for School

Figure 18-7 Intersection Choker

Figure 18-8 Turn Prohibitors

Figure 18-9 Semi-Diverters

Figure 18-10 Lane Eliminating Choker

Figure 18-11 Diagonal Diverters

Figure 18-12 Realigned Intersections

Page 18-ii Larimer County Urban Area Street Standards – Repealed and Reenacted April 1, 2007

Adopted by Larimer County, City of Loveland, City of Fort Collins

Chapter 18 – NEIGHBORHOOD TRAFFIC SAFETY Section 18.1 General

CHAPTER 18 – NEIGHBORHOOD TRAFFIC SAFETY

18.1 GENERAL

This chapter presents acceptable methods of neighborhood traffic calming that are determined by

the Local Entity to be necessary for existing Local and Minor Collector Roadways. This chapter

also provides for specific design criteria for a number of traffic calming methods.

18.1.1 Intended Use

The necessity or desire for traffic safety and calming stems from the perception that

Local and Minor Collector Roadways, particularly in residential areas, do not always

function as intended. These roadways should be low traffic volume roadways used for

direct access to residences on the street. They are also intended as a multi-modal system

that is shared by vehicular, bicycle, and pedestrian traffic equally, in a manner that

minimally impacts residents in these areas.

18.1.2 Traffic Calming for New Street Design

The devices presented in this chapter are generally not intended for use on new roadways.

New roadway design is addressed in Chapter 7, Street Design and Technical Criteria.

New (local streets and minor collectors) are to be designed to minimize cut through

traffic, high volumes, and high speed operation and to maximize the efficiency of the

roadway to provide vehicular access and bicycle and pedestrian traffic.

18.1.3 Roundabouts and Mini Roundabouts

Roundabouts and Mini Roundabouts, considered traffic control measures, are included in

Chapter 8, Intersections. These traffic control measures may be used in new or existing

street design if the appropriate criteria are met.

18.2 TRAFFIC SAFETY PROBLEMS

Some residents in certain residential areas maintain that excessive speed, volume, or cut-through

traffic is unacceptable. The resident believes the presence of too many vehicles traveling at high

speeds diminishes that neighborhood’s quality of life. Traffic calming measures are intended to

minimize these issues and return the quality of life to the neighborhood. Care must be taken by

the designer so that the installation of traffic calming devices does not create unintended hazards

that delay emergency response or jeopardize the safety of bicyclists, pedestrians or motorists.

18.2.1 Speeding

Speeding may occur on roadways that allow the driver to feel safe while exceeding the

posted speed limit. Factors that contribute to this perception include long, unbroken lines

of sight, steep roadway grades, wide roadways, low density developments, low pedestrian

activity, and large building setbacks. In addition, speeding may occur when the street

functions as a higher classification street than originally intended.

Larimer County Urban Area Street Standards – Repealed and Reenacted April 1, 2007 Page 18-1 Adopted by Larimer County, City of Loveland, City of Fort Collins

Chapter 18 – NEIGHBORHOOD TRAFFIC SAFETY Section 18.3 Traffic Calming Design Criteria

18.2.2 Measuring Speed of Roadway

The standard method of measuring speed on any street is the determination of the 85th

percentile speed. The 85th percentile speed is the speed at which or below which 85

percent of the vehicles travel. If the 85th percentile speed is at or below the posted speed

limit, a speeding problem does not exist. However, if the 85th percentile speed is over the

posted speed limit by 5 miles per hour or greater, either the posted speed limit may be

inappropriate or a speeding problem may exist. Many other factors must be evaluated for

determining speed limit.

18.2.3 Intrusion (Cut-Through Traffic)

Intrusion is increased volume or excessive non-local traffic along a neighborhood street.

This cut-through traffic is caused by drivers who use a Local Street to go through a

neighborhood and save time on their trip. Local Streets that are less impeded than other

local streets within the same neighborhood will often invite cut-through traffic. Routes

that are perceived to be time-saving will attract more traffic. This increased cut-through

traffic can cause a local street to function more like a Collector.

18.2.4 Pedestrian Safety

Pedestrian safety is a concern on streets experiencing speeding vehicles, cut-through

traffic, or a combination of these problems. The high concern areas are in the vicinity of

neighborhood schools and parks or mid-block pedestrian crossings, particularly on streets

with on-street parking. These areas require special consideration for the mobility and

safety of the pedestrian.

18.3 TRAFFIC CALMING DESIGN CRITERIA

For existing Local or Minor Collectors that are defined for Traffic Calming. Refer to the City of

Loveland’s Traffic Calming Procedures. Refer to the City of Fort Collins’ Traffic Calming

Procedures. This chapter describes design criteria for the engineered solutions. It does not state

when or where these improvements are to be used.

18.3.1 Speed Limit Signs

Refer to Chapter 14, Traffic Signals, Signing, and Striping

18.3.2 Speed Humps

Refer to Construction Drawing 1801F and 1802F for design criteria in Fort Collins

(GMA and city limits).

18.3.3 Dips

Refer to Chapter 8, Intersections, for standard Crosspan design.

Page 18-2 Larimer County Urban Area Street Standards – Repealed and Reenacted April 1, 2007

Adopted by Larimer County, City of Loveland, City of Fort Collins

Chapter 18 – NEIGHBORHOOD TRAFFIC SAFETY Section 18.3 Traffic Calming Design Criteria

18.3.4 Mini Roundabouts

Refer to Chapter 8, Intersections for Mini Roundabout design requirements.

18.3.5 Neckdowns

When neckdowns are used they must be designed to maintain a constant cross fall in the

pavement surface. Refer to Figure 18-1 for design criteria.

18.3.6 Traversable Barriers

Refer to Figure 18-2 for design criteria.

18.3.7 Deviations (Chicanes)

Refer to Figure 18-3 for design criteria.

18.3.8 Raised Intersections

Refer to Figure 18-4 for design criteria.

18.3.9 Neighborhood Identification Island

Refer to Figure 18-5 for design criteria.

18.3.10 Drop Off Zone for Schools

Refer to Figure 18-6 for design criteria.

18.3.11 Intersection Chokers

Refer to Figure 18-7 for design criteria.

18.3.12 Turn Prohibitors

Refer to Figure 18-8for design criteria.

18.3.13 Semi-Diverters

Refer to Figure 18-9for design criteria.

18.3.14 Lane Eliminating Choker – Loveland (GMA and city limits)

Refer to Figure 18-10 for design criteria.

18.3.15 Diagonal Diverters

Refer to Figure 18-11 for design criteria.

Larimer County Urban Area Street Standards – Repealed and Reenacted April 1, 2007 Page 18-3 Adopted by Larimer County, City of Loveland, City of Fort Collins

Chapter 18 – NEIGHBORHOOD TRAFFIC SAFETY Section 18.3 Traffic Calming Design Criteria

18.3.16 Realigned Intersections

Refer to Figure 18-12 for design criteria.

Page 18-4 Larimer County Urban Area Street Standards – Repealed and Reenacted April 1, 2007

Adopted by Larimer County, City of Loveland, City of Fort Collins

20'-0" min. FL to FL

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PLAN VIEW

1. Only full sections of sidewalk may be removed.

NECKDOWNS

15' R Match Existing Flow Line

LARIMER COUNTY DESIGN REVISION NO: URBAN AREA FIGURE STREET STANDARDS DATE: 08/07/00

FIGURE

18-1

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1 . Jersey Barriers may be used as temporary Traversable Barriers upon approval.

TRAVERSABLE BARRIERS LARIMER COUNTY DESIGN REVISION NO:

URBAN AREA FIGURE STREET STANDARDS DATE: 08/07/00

FIGURE

18-2

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50' R (min.)

1 . Deviations must cause driver to change directions. 2. Medians may be included in design to assist in the separation of traffic. 3. Narrow roadway wanders in a street right of way; requires wide ROW. 4. For min. curb radii, see Chapter 8, Tables 8-1 & 8-2.

DEVIATIONS (CHICANES) LARIMER COUNTY DESIGN REVISION NO:

URBAN AREA FIGURE STREET STANDARDS DATE: 08/07/00

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RAISED INTERSECTIONS LARIMER COUNTY DESIGN REVISION NO: FIGURE

URBAN AREA FIGURE STREET STANDARDS DATE: 08/07/00 18-4

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1. Sign cannot impair sight distance. 2. The sign (in Fort Collins) must meet the following criteria:

•Sign must have a max height of 5'. • sign surface area must be 24 square feet (max.) • The word "neighborhood" must be included in the signage lettering.

NEIGHBORHOOD IDENTIFICATION ISLAND LARIMER COUNTY DESIGN REVISION NO:

URBAN AREA FIGURE STREET STANDARDS DATE: 08/07/00

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DROP OFF ZONE FOR SCHOOL LARIMER COUNTY DESIGN REVISION NO: 1 FIGURE

URBAN AREA FIGURE STREET STANDARDS DATE: 04/01/07 18-6

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INTERSECTION CHOKER LARIMER COUNTY DESIGN REVISION NO: FIGURE

URBAN AREA FIGURE STREET STANDARDS DATE: 08/07/00 18-7

"DO NOT ENTER" Sign: R5-1 ----

NOTE:

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1 . Any landscaping provided must be maintained by HOA City Forester or private owner; otherwise, area must be hardscaped.

TURN PROHIBITORS LARIMER COUNTY DESIGN REVISION NO: FIGURE

URBAN AREA FIGURE STREET STANDARDS DATE: 08/07/00 18-8

"DO NOT ENTER" Sign: R5-1

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1 . Any landscaping provided must be maintained by HOA, City Forester or private owner; otherwise, area must be hardscaped.

SEMI - DIVERTERS LARIMER COUNTY DESIGN REVISION NO:

URBAN AREA FIGURE STREET STANDARDS DATE: 08/07/00

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LANE ELIMINATING CHOKER LARIMER COUNTY DESIGN REVISION NO: FIGURE

URBAN AREA FIGURE STREET STANDARDS DATE: 08/07/00 18-10

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LARIMER COUNTY URBAN AREA

STREET STANDARDS

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DESIGN REVISION NO: FIGURE FIGURE DATE: 08/07/00 18-11

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REALIGNED INTERSECTIONS LARIMER COUNTY DESIGN REVISION NO: FIGURE

URBAN AREA FIGURE STREET STANDARDS DATE: 08/07/00 18-12