Kansas LTAP Proven Safety Countermeasures Webinar Series · 2017. 12. 4. · Kansas LTAP Proven...

Kansas LTAP

Proven Safety CountermeasuresWebinar Series

November 14, 28, and December 5, 201710:00 a.m. to 11:00 p.m. CST

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WELCOMEPresenter:

Mehrdad Givechi, PE, PTOEProgram [email protected]

Hosted by Kansas LTAP

Contact: Kristin Kelly, MPAEducation Program Coordinator (785) [email protected]

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Agenda:• History of Proven Safety Countermeasures initiative

(PSCi)

• Intersections

• Roadway Departures

• Pedestrians & Bicycles

• Crosscutting Strategies

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• Version 1.0 was initiated in 2008

• Version 2.0 released in 2012

• Version 3.0 released in 2017

A Brief History of the PSCi

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• First nine “proven safety countermeasures” 3 related to intersection safety 3 related to roadway departure safety 2 related to pedestrian and bicycle safety 1 crosscutting strategy

• Envisioned as a means to boost systemic implementation

• Began tracking implementation progress

PSCi Version 1.0

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• Retained four of the original nine PSCs

• Added five new countermeasures 2 related to intersection safety 1 related to road departure safety 2 related to pedestrian and bicycle safety

• New progress tracking approach anchored to Focus State status and SHSP Emphasis Areas

• Began tracking implementation progress

PSCi Version 2.0

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FHWA formed working groups to review the PSCi

• First group evaluated the overall initiativesWidely popular and has established a valued brand Consensus to continue the PSCi with minor tweaks

• Second group vetted candidates for the update Identified and evaluated 31 candidate countermeasures and strategies

PSCi Version 3.0

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• Six new countermeasures were added 2 related to intersection safety 1 related to roadway departure safety 1 related to pedestrian and bicycle safety 2 crosscutting strategies

• Bringing the total number of PSCs to 207 related to intersection safety5 related to road departure safety5 related to pedestrian and bicycle safety3 crosscutting strategies

PSCi Version 3.0

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Reaffirming a Data-Driven Approach

“Our partners should continue to strengthen their evidence-based decision-making processes…and systemic planning approaches to make improved safety investment decisions.”

2017 PSCi Guidance Memo

PSCi Version 3.0

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Reaffirming a Data-Driven Approach

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FHWA will continue to support States and other safety partners’ efforts to:

• Conduct appropriate analysis of quality safety data

• Use evidence-based framework for decision-making

• Use the CMF Clearinghouse to choose appropriate countermeasures

• Consider the proven safety countermeasures as viable options

FHWA Proven Safety Countermeasuresfor

Intersections

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1. Roundabouts

Roundabouts have fewer number of conflicts points compared to other conventional intersections

Safety Benefits Tw-Way Stop-Controlled Intersection to a RAB: 82% reduction in severe

crashes Signalized Intersection to a RAB: 78% reduction in severe crashes

PSCi (ver. 1) - Intersections

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8 Vehicle Conflict Points

8 Ped. Conflicts Points

Intersection Conflict Points

Roundabouts …

• Work well for heavy left turn or crossroad traffic

• Are Safe and efficient if designed properly

• Difficult for pedestrians with poor vision

• May not work well in high pedestrian traffic areas

Roundabouts …

• Can have as few as three legs and as many as six legs

• Do not have to be perfectly circular. It can be oval, tear-drop, peanut or dogbane in shape

• Can be very small and simple (e.g. mini roundabout) or be very large and complex (e.g. multilane roundabouts)

2. Left- and Right-turn Lanes at Two-Way Stop Controlled Intersections

Provide physical separation between turning movements and through movements

Safety Benefits Left-Turn Lanes: 28% - 48% reduction in total number of crashes Right-Turn Lanes: 14% -26% reduction in total number of crashes


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3. Yellow Change Interval

Properly timed yellow clearance (change) interval is one method to

protect motorists from getting trapped in the dilemma zone at signalized intersections

Safety Benefits 36% - 50% reduction in red light running crashes 8% -14% reduction in total number of crashes 12% reduction in injury crashes


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Dilemma Zone Definition

As defined in the ITE Traffic Detector Handbook

“That portion of the roadway in advance of the intersectionwithin which a driver is indecisive regarding stopping priorto the stop line or proceeding into or through theintersection.”

4. Corridor Access Management

Balancing overall safety and corridor mobility for all users along with the access needs of adjacent land uses

Safety Benefits Along 2-Lane Rural Roads: 5% - 23% reduction in total number of

crashes Along Urban/Suburban Arterials: 25% -31% reduction in injury and fatal

crashes


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Access Management strategies

• Driveway closure, consolidation, or relocation

• Restricted access designs (RI/RO, RI/RO/LI, Roundabout, etc)

• Turn lanes (RT, LT, TWLTL)

• Frontage Roads

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Positive Offset for Left-Turn Lanes

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5. Backplates with Retroreflective Borders

Enhancing Traffic Signal Visibility by providing controlled-contrast

background

Safety Benefits 15% reduction in total number of crashes


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6. Systemic Application of Multiple Low-Cost Countermeasures at Stop-Controlled Intersections(New)

Enhancing driver’s awareness and recognition of the intersections

Safety Benefits 10% reduction in injury and fatal crashes 15% reduction in nighttime crashes

PSCi (ver. 3) – Intersections

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Application

• Mostly signing and pavement marking enhancements

• Strategy relies on cost economy and treatment saturation

• Best suited for intersections with under 20,000 AADT total entering

7. Reduced Left-Turn Conflict Intersection (New)

Reducing conflict points of severe type by geometric alteration

Safety Benefits Restricted Crossing U-Turn (RCUT): 54% reduction in injury and fatal

crashes; and 35% reduction in all crashes

Median U-Turn (MUT): 30% reduction in injury and fatal crashes; and 16% reduction in all crashes

PSCi (ver. 3) – Intersections

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• Minor road through and left-turn movements are re-routed to downstream U-turns on major road

• Treatment of major road movements is optional

• Highly beneficial for divided high-speed highways with unsignalized at-grade intersections.

Restricted Crossing U-Turn (RCUT)

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• Major road LT is re-routed to downstream U-turns on major road• Treatment of minor road movements is optional• Beneficial at locations with high through volumes and moderate to low left-

turn volumes• Signal phasing / timing advantages at signalized intersections

Median U-Turn (MUT)


Roadway Departures

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8. Longitudinal Rumble Strips and Stripes along Two-Lane Highways

Increasing driver’s awareness via audible means

Safety Benefits Centerline Rumble Strips: 44% - 64% reduction in head-on, opposite-

direction and sideswipe injury and fatal crashes Shoulder Rumble Strips: 13% -51% reduction in single vehicle, run-off-

road injury and fatal crashes

PSCi (ver. 1) – Roadway Departure

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• Rumble strips are intended to supplement pavement markings

• Adds sound and vibration to the visual benefits of painted markings

• Provides a drowsy, inattentive, or distracted driver with a clear warning that the vehicle has left travel lane

• Provides some reaction time before the vehicle leaves the road

9. Median Barrier

Reducing head-on / opposing sideswipe collisions by keeping

vehicles from crossing the median

Safety Benefits 8% of all fatalities on divided highways are due to head-on crashesMedian barriers installed on rural four-lane freeways reduce cross-

median crashes by 97%


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Types of Median Barriers

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• Cable Barriers (Flexible)▫ High deformation and deflection▫ Absorbs most of the crash energy with little redirection▫ More adaptable to slopes in medians▫ Low installation cost

• Beam Guardrails (Semi-Rigid)▫ Some deformation and deflection▫ Absorb some of the crash energy with some redirection▫ Moderate installation cost

• Concrete Barriers (Rigid)▫ Little to no deflection▫ Absorb little crash energy with nominal redirection▫ Expensive

10. Safety Edge

Reducing edge drop-off type crashes by helping errant vehicles to

maintain and/or regain stability on roadway re-entry

Safety Benefits 11% reduction in injury and fatal crashes


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Pavement Edge Rutting and Drop-Offs

• Edge rutting occurs on all sections of roads

• Usually a small percentage of road length

• Caused by errant vehicles in conjunction with erosion

• Common in curves and near turning movements

• Mailboxes

11. Enhanced Delineation and Friction for Horizontal Curves

Reducing run-off road collisions on horizontal curves by improving visibility via delineation; and application of high skid-resistant pavement material

Safety Benefits Chevron Signs: 24% reduction in nighttime crashes, and 16% reduction in

non-intersection injury and fatal crashes High Friction Surface Treatment (HFST): 52% reduction in wet road crashes,

and 24% reduction in curve crashes


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Treatments• Advance Warning Signs▫ Curve or Turn Signs▫ Advisory Speed Plaque Sings

• Chevron Signs

• Delineators

• Pavement Markings▫ Edge line▫ Centerline

• High Friction Surface Treatment (HFST)

12. Roadside Design Improvements at Curves (New)

Providing safe recovery area along the outside of horizontal curves

Safety Benefits 27% of all fatal crashes occur at curves, 80% of which are roadway

departure crashes Increasing the clear zone at curves reduce severity of the roadway

departure crashes between 22% and 44%.


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What is Clear Zone?

1. A roadside area free of dangerous fixed objects, slopes, etc.

2. Available for safe use by errant vehicles

3. May consist of a shoulder, recoverable slope, or non-recoverable (traversable) slope

• Increase Clear Zone at Curves▫ Recommended by AASHTO Roadside Design Guide▫ Proven to reduce fatal and sever injury crashes

• Improve Traversability▫ Add or widen shoulders in curves▫ Flatter slopes at curves than in tangent sections

Recoverable - 4:1 or flatter

Non-Recoverable - 3:1 to 4:1

Non-Traversable - steeper than 3:1

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Order of Treatment1. Remove the obstacle

2. Relocate the obstacle to a safer place

3. Redesign the obstacle

4. Reduce impact severity

5. Shield with guardrail

6. Delineate to guide drivers around it

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Relocate the Hazard

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Redesign the Hazard• Make drainage features traversable

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Redesign the Hazard• Make objects breakaway

Post behind stub

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Reduce Impact Severity• Use crash cushions or impact attenuators

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Shield with Guardrail• Deflection Distance

• Type of Guardrail▫ Flexible▫ Semi-rigid▫ Rigid

• Right Height

• Length of Need

• End Treatment

• AASHTO Roadside Design Guide


Pedestrians & Bicycles

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13. Medians and Pedestrian Crossing Islands in Urban and Suburban Areas

Reducing crashes involving pedestrians crossing roadway

Safety Benefits Raised Median: 46% reduction in pedestrian crashes Pedestrian Refuge Island: 56% reduction in pedestrian crashes

PSCi (ver. 1) – Pedestrians & Bicycles

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14. Walkways

Reducing crashes involving pedestrians walking along

roadways

Safety Benefits Sidewalks: 65% - 89% reduction in pedestrian crashes Paved Shoulders: 71% reduction in pedestrian crashes


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15. Pedestrian Hybrid Beacon (PHB)(a.k.a. High intensity Activated crossWalK-HAWK)

Reducing crashes involving pedestrians crossing roadway

Safety Benefits 69% reduction in pedestrian crashes 29% reduction in total crashes 15% reduction in serious injury and fatality crashes


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Required minimum number of signal heads (faces) = 2 per approach On single lane approaches, install one head on the side and one over the roadway On multilane approaches

Either A signal head (face) should be installed on each side of the approach if a median of sufficient

width existsOR At least one of the signal heads (faces) should be installed over the roadway

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Required minimum number of signal heads (faces) = 2 per approach For speeds > 35 mph OR operating conditions obstructing roadside visibility install both heads (faces) over the roadway

16. Road Diet (a.k.a. Road Reconfiguration)

Reducing crashes by reconfiguring roadway cross-section to provide a complete street for all road users

Safety Benefits 4-Lane to 3-Lane: 19% - 47% reduction in total crashes


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Application

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• Less than 10,000 ADT: Great candidate in most cases. Capacity will most likely not be affected

• 10,000 – 15,000 ADT: Good candidate in many cases. Conduct intersection analysis and consider signal retiming to determine any effect on capacity

• 15,000 – 20,000 ADT: Good candidate in some cases. Conduct a corridor analysis. Capacity may be affected depending on the “before” condition

• Greater than 20,000 ADT: Complete a feasibility study to determine whether this is a good candidate. There are some examples nation-wide that Road Diets have been successful with ADTs as high as 26,000. Capacity may be affected.

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Benefits of Road Diet • Reduction in rear-end and left-turn crashes due to provision of

dedicated left-turn lane• Reduction in right-angle crashes as side street vehicles cross

less travel lanes• Fewer lanes for pedestrians to cross• Opportunity to install pedestrian refuge islands, bicycle lanes,

on-street parking, or transit stops• Traffic calming and more consistent speed• A more community-focused, “Complete Street” environment

that better accommodates the needs of all road users.

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Road Diet Pro’s Road Diet Con’s

Slows TrafficEliminates speeding and merge-and-weave driving. Slower trafficin downtown areas encourages window- shopping and looking

at stores.

Slows TrafficThrough traffic travels in one lane and therefore is limited by

the speed of the slowest driver

Improves SafetyFewer crashes because left-turning movements are removed

from the through travel lane

May cause difficulty in pulling out into the roadway from adriveway or side- street if traffic volumes are high (above 15,000

vehicles per day) especially during peak hours, because of lack ofgaps in the travel lane

Ability to utilize the existing right-of-way for other purposes such as bicycle lanes, parking, or streetscape enhancements

Slight decrease in roadway capacity, due to loss of a through lane in each direction

Inexpensive roadway design fix, especially when implementedas part of an existing repaving project If road diet is on a bus route, bus stops can stop traffic

Ability to improve lane width to standard 12 ft. where roads aretoo narrow and not meeting standards.

Driver ExpectationsPeople used to driving on the road as a 4-lane will have to

get used to the 3-lane configuration

17. Leading Pedestrian Intervals (New)

Reducing crashes involving pedestrians at signalized

intersections by enhancing their visibility

Safety Benefits 60% reduction in pedestrian-vehicle crashes


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Leading Pedestrian Interval

• Pedestrians get “WALK” signal before vehicles get green light

• Provides pedestrians a 3 – 7 seconds head start before vehicles are given a green indication

• Allows pedestrians to establish presence in crosswalk before vehicles have priority to turn left and/or right

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Benefits of Leading Pedestrian Interval

• 60% Reduction in pedestrian-vehicle crashes at intersections

• Increases visibility of crossing pedestrians

• Reduces conflicts between pedestrians and vehicles

• Increases likelihood of motorists yielding to pedestrians

Guidance

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FHWA’s Handbook for Designing Roadways for the Aging Population – Use at intersections with high turning vehicle volumes

MUTCD Chapter 4E.06 – Pedestrian Intervals and Signal Phases


All Road UsersUsing Crosscutting Strategies

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18. Road Safety Audits (a.k.a. Road Safety Assessment)

Reducing crashes involving all road users

Safety Benefits 10% - 60% reduction in total crashes

PSCi (ver. 1) – Crosscutting Strategies

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What is RSA?A road safety assessment is a

formal safety performance examination of an existing or future road or intersection

by an independent assessment team.

Formal: procedures and documentation

Safety Performance: focus on safety

Independent: no previous experience with the road

Assessment Team: general experience and specialists

Traditional Road Safety Review vs. RSA

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• Reactive• In-House Team• No Field Review• Standards Compliance

• Proactive• Independent Team• Field Reviews• Comprehensive, with

Human Factors

Traditional RSR RSA

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• considers the safety of all road users.

• considers interactions at the limits of the project.

• examines the interaction of project elements.

• may proactively consider mitigation measures

An RSA also…

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When do we conduct RSA?

• Pre-Construction:▫ planning / feasibility▫ preliminary (draft) design▫ detailed design

• Construction:▫ work zones▫ pre-opening

• Post-Construction/Operational:▫ existing roads / in-service roads

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Step 1

Identify Project

RSA Responsibilities

Step 2

Select RSA Team

Step 3Conduct Start-Up Meeting

Step 4Perform

Field Review

Step 5Conduct

Analysis & Prepare Report

Step 6Present

Findings to Project

Owner

Step 7

Prepare Formal

Response

Step 8

Incorporate Findings

Design Team/Project Owner Responsibility

RSA Team Responsibility

19. Local Road Safety Plans (LRSP) (New)

Local roads experience 3 times the fatality rate than the Interstate

Highway Systems

Safety Benefits Reduction in total crashes


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Local Roads Safety Plan

• Developing an LRSP is an effective strategy to improve local road safety

• An LRSP is a coordinated plan that provides a comprehensive framework for reducing fatalities and serious injuries on local roads within a specific jurisdiction

• An LRSP is flexible and utilizes the 4 E’s as appropriate to establish and gain support for an agency’s local safety goals, objectives, and key emphasis areas

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Benefits of Local Roads Safety Plan• Enhanced safety awareness among stakeholders

• Establish partnerships representing Engineering, Enforcement, Education, and Emergency medical services

• Collaboration among municipal, county, Tribal, State and/or Federal entities

• Identification of target crash types and crash risk and safety countermeasures

• Leverage Safety Funds

• Informed Safety Priorities

• Complements the State Strategic Highway Safety Plan (SHSP)

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Steps in LRSP Development Process• Step 1 – Establish Leadership

• Step 2 – Analyze the Safety Data

• Step 3 – Determine Emphasis Areas

• Step 4 – Identify Strategies

• Step 5 – Prioritize and Incorporate Strategies

• Step 6 – Evaluate and Update the LRSP

20. USLIMITS2 (New)

Help practitioners assess and establish safe, reasonable and

consistent speed limits

Safety Benefits Reduction in speed related crashes


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Why USLIMITS2?

• Speed limits need to be credible and enforceable

• Need a tool that considers all factors impacting speed and safety of road users, such as 50th and 85th percentile speeds Traffic volumes Roadway type Roadway characteristics (roadside, number of access drives, etc.) Crash data

• Need for an Expert System to improve decision making process

• Supported by FHWA and funded by AASHTO (NCHRP Project 3-67)

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Benefits of USLIMITS2 • Free and easy to use web-based tool

• Decision rule expert system with consideration of factors impacting speeds

• Consistent, credible, enforceable speed limits

• Increase transparency of the methods used to determine speed limits

• Supports motorists’ acceptance of and compliance with speed limits

• Helps in responding to public and political concerns

• Takes out all the emotion and politics, and provides concrete and easy to understand solution to speed zoning

Next Steps

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October-November 2017Office of Safety will work with field offices to baseline current status of each NEW PSC

January 2018Begin formal efforts to advance implementation

June 2018 (and subsequent 6-mo intervals)Office of Safety will request progress updates from field offices.

Available Resourceshttp://safety.fhwa.dot.gov/provencountermeasures

• 1-pager fact sheets• Slides from webinar and link to recorded session• Links to additional FHWA resources for each countermeasure

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Contacts for Further InformationIntersection Countermeasures

Jeffrey Shaw [email protected] 708-283-3524

Roadway Departure CountermeasuresMenna Yassin [email protected] 202-366-2833Cathy Satterfield [email protected] 708-283-3552

Pedestrian/Bicycle CountermeasuresTamara Redmon [email protected] 202-366-4077

Crosscutting StrategiesLRSPRosemarie Anderson [email protected] 202-366-5007RSABecky Crowe [email protected] 804-775-3381USLIMITS2Guan Xu [email protected] 202-366-5892

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Copy of the slide presentation and recorded webinar sessions are available on Kansas LTAP website at

https://kutc.ku.edu/training-webinars

Thank you

Proven Safety Countermeasures Webinar Series

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