Proven Safety Countermeasures Webinar Series

Transcription

1 1 Kansas LTAP Proven Safety Countermeasures Webinar Series November 14, 28, and December 5, :00 a.m. to 11:00 p.m. CST

2 2 WELCOME Presenter: Mehrdad Givechi, PE, PTOE Program Engineer Hosted by Kansas LTAP Contact: Kristin Kelly, MPA Education Program Coordinator (785)

3 3 Agenda: History of Proven Safety Countermeasures initiative (PSCi) Intersections Roadway Departures Pedestrians & Bicycles Crosscutting Strategies

4 4 A Brief History of the PSCi Version 1.0 was initiated in 2008 Version 2.0 released in 2012 Version 3.0 released in 2017

5 5 PSCi Version 1.0 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

6 6 PSCi Version 2.0 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

7 7 PSCi Version 3.0 FHWA formed working groups to review the PSCi First group evaluated the overall initiatives Widely 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

8 8 PSCi Version 3.0 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 20 7 related to intersection safety 5 related to road departure safety 5 related to pedestrian and bicycle safety 3 crosscutting strategies

9 9 PSCi Version 3.0 Reaffirming a Data-Driven Approach Our partners should continue to strengthen their evidencebased decision-making processes and systemic planning approaches to make improved safety investment decisions PSCi Guidance Memo

10 10 Reaffirming a Data-Driven Approach 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

11 FHWA Proven Safety Countermeasures for Intersections 11

12 12 PSCi (ver. 1) - Intersections 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

13 13 Intersection Conflict Points 8 Vehicle Conflict Points 8 Ped. Conflicts Points

14 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

15 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, teardrop, 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)

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18 18 PSCi (ver. 1) - Intersections 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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20 20 PSCi (ver. 1) - Intersections 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

21 21 Dilemma Zone Definition As defined in the ITE Traffic Detector Handbook That portion of the roadway in advance of the intersection within which a driver is indecisive regarding stopping prior to the stop line or proceeding into or through the intersection.

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24 24 PSCi (ver. 2) - Intersections 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

25 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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32 Positive Offset for Left-Turn Lanes 32

33 Positive Offset for Left-Turn Lanes 33

34 Positive Offset for Left-Turn Lanes 34

35 35 PSCi (ver. 2) - Intersections 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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38 38 PSCi (ver. 3) Intersections 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

39 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

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43 43 PSCi (ver. 3) Intersections 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

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45 45 Restricted Crossing U-Turn (RCUT) 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 highspeed highways with unsignalized atgrade intersections.

46 46 Median U-Turn (MUT) 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 leftturn volumes Signal phasing / timing advantages at signalized intersections

47 FHWA Proven Safety Countermeasures for Roadway Departures 47

48 48 PSCi (ver. 1) Roadway Departure 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, oppositedirection and sideswipe injury and fatal crashes Shoulder Rumble Strips: 13% -51% reduction in single vehicle, run-offroad injury and fatal crashes

49 49 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

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52 52 PSCi (ver. 1) Roadway Departure 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 crashes Median barriers installed on rural four-lane freeways reduce crossmedian crashes by 97%

53 53 Types of Median Barriers 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

54 54 PSCi (ver. 1) Roadway Departure 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

55 55 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

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57 57 PSCi (ver. 2) Roadway Departure 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

58 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)

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64 64 PSCi (ver. 3) Roadway Departure 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%.

65 65 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

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

67 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

68 68 Order of Treatment 1. 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

69 Relocate the Hazard 69

70 70 Redesign the Hazard Make drainage features traversable

71 71 Redesign the Hazard Make objects breakaway Post behind stub

72 72 Reduce Impact Severity Use crash cushions or impact attenuators

73 73 Shield with Guardrail Deflection Distance Type of Guardrail Flexible Semi-rigid Rigid Right Height Length of Need End Treatment AASHTO Roadside Design Guide

74 FHWA Proven Safety Countermeasures for Pedestrians & Bicycles 74

75 75 PSCi (ver. 1) Pedestrians & Bicycles 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

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79 79 PSCi (ver. 1) Pedestrians & Bicycles 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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81 81 PSCi (ver. 2) Pedestrians & Bicycles 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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83 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 exists OR At least one of the signal heads (faces) should be installed over the roadway 83

84 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 84

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86 86 PSCi (ver. 2) Pedestrians & Bicycles 16. Road Diet (a.k.a. Road Reconfiguration) Reducing crashes by reconfiguring roadway crosssection 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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88 88 Application 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 nationwide that Road Diets have been successful with ADTs as high as 26,000. Capacity may be affected.

89 89 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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91 91 Road Diet Pro s Road Diet Con s Slows Traffic Eliminates speeding and merge-and-weave driving. Slower traffic in downtown areas encourages window- shopping and looking at stores. Improves Safety Fewer crashes because left-turning movements are removed from the through travel lane Slows Traffic Through traffic travels in one lane and therefore is limited by the speed of the slowest driver May cause difficulty in pulling out into the roadway from a driveway or side- street if traffic volumes are high (above 15,000 vehicles per day) especially during peak hours, because of lack of gaps 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 implemented as 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 are too narrow and not meeting standards. Driver Expectations People used to driving on the road as a 4-lane will have to get used to the 3-lane configuration

92 92 PSCi (ver. 3) Pedestrians & Bicycles 17. Leading Pedestrian Intervals (New) Reducing crashes involving pedestrians at signalized intersections by enhancing their visibility Safety Benefits 60% reduction in pedestrian-vehicle crashes

93 93 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

94 94 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

95 95 Guidance 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

96 FHWA Proven Safety Countermeasures for All Road Users Using Crosscutting Strategies 96

97 97 PSCi (ver. 1) Crosscutting Strategies 18. Road Safety Audits (a.k.a. Road Safety Assessment) Reducing crashes involving all road users Safety Benefits 10% - 60% reduction in total crashes

98 98 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: Assessment Team: no previous experience with the road general experience and specialists

99 99 Traditional Road Safety Review vs. RSA Traditional RSR RSA Reactive In-House Team No Field Review Standards Compliance Proactive Independent Team Field Reviews Comprehensive, with Human Factors

100 100 An RSA also 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

101 101 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

102 102 RSA Responsibilities Design Team/Project Owner Responsibility RSA Team Responsibility Step 1 Identify Project Step 2 Select RSA Team Step 3 Conduct Start-Up Meeting Step 4 Perform Field Review Step 5 Conduct Analysis & Prepare Report Step 6 Present Findings to Project Owner Step 7 Prepare Formal Response Step 8 Incorporate Findings

103 103 PSCi (ver. 3) Crosscutting Strategies 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

104 104 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

105 105 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)

106 106 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

107 107 PSCi (ver. 3) Crosscutting Strategies 20. USLIMITS2 (New) Help practitioners assess and establish safe, reasonable and consistent speed limits Safety Benefits Reduction in speed related crashes

108 108 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 50 th and 85 th 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)

109 109 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

110 110 Next Steps October-November 2017 Office of Safety will work with field offices to baseline current status of each NEW PSC January 2018 Begin formal efforts to advance implementation June 2018 (and subsequent 6-mo intervals) Office of Safety will request progress updates from field offices.

111 Available Resources 1-pager fact sheets Slides from webinar and link to recorded session Links to additional FHWA resources for each countermeasure 111

112 112 Contacts for Further Information Intersection Countermeasures Jeffrey Shaw Roadway Departure Countermeasures Menna Yassin Cathy Satterfield Pedestrian/Bicycle Countermeasures Tamara Redmon Crosscutting Strategies LRSP Rosemarie Anderson RSA Becky Crowe USLIMITS2 Guan Xu

113 113 Copy of the slide presentation and recorded webinar sessions are available on Kansas LTAP website at

114 114 Thank you Proven Safety Countermeasures Webinar Series