Texas Intersection Safety Implementation Plan Workshop JUNE 2, 2016

Transcription

1 Texas Intersection Safety Implementation Plan Workshop JUNE 2, 2016

2 Why Intersection Safety? A small part of overall highway system, but Each year roughly 50% of all crashes estimated 3 million involve intersections 9

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4 Texas: 802 Intersection Fatalities (2014) 12

5 Why a systemic approach for intersections? Realizing the SHSP Vision and Goals The general consensus among those involved in transportation safety is that further reductions are not only desirable, but feasible. BUT achieving means new tools, new approaches, new ideas 13

6 Texas SHSP Intersection 15

7 Texas SHSP Pedestrians 16

8 Approaches to Saving Lives and Preventing Serious Injuries Traditional Systemic Comprehensive Policy Culture 17

9 Conventional vs. Systematic Conventional/Traditional: Based on High crash Locations Purely reactive; identified by very high number of crashes at specific intersection Usually involves application of countermeasures with high CRF values, but also at high cost (e.g., reconstruction or widening) Usually fewer than per year in a average size state By itself, negligible impact on reducing statewide fatalities Traditional Systemic Comprehensive Policy Culture 18

10 Conventional vs. Systematic Systematic/Comprehensive Reverses the traditional approach, then enhances it Start with known effective, low cost countermeasures Install systematically at large number of intersections with both moderate and high crash histories where cost effective results are expected Typically find that 3 8% of the intersections with any crash history account for 25 40% of the statewide intersection problem Substantial reduction of statewide intersection injuries/ fatalities can be realized with this approach (ties directly to SHSP goals) Plan can be tailored to available resources Can also include a Corridor/Community 3E component Traditional Systemic Comprehensive Policy Culture 19

11 Basic Approach for Intersections 20

12 Key: Making Intersections Incrementally Safer Increase visibility of intersections and traffic control devices Increase awareness of intersections Improve the design of intersections to reduce conflicts Improve driver comprehension to reduce confusion Improve the operations of intersections Improve sight distance at intersections Improve driver compliance with traffic control devices 21

13 The End Goal It is estimated that deploying these countermeasures will cost $ M and prevent fatalities and serious injuries over a _ year period. The projected Benefit Cost Ratio is approximately :1 With continued observation/evaluation, most successful treatments to be considered for systemwide policy/standardization 22

14 Recognizing the Systemic Approach New Emphasis in MAP 21: The term systemic safety improvement means an improvement that is widely implemented based on high risk roadway features that are correlated with particular crash types, rather than crash frequency. 23

15 FAS-INT: Systemic Intersection Safety Plans From 2008-Current *Multiple ISIPs in TX DC PR FLH Intersection Safety Implementation Plan (ISIP) completed through HSA-FAS State considering or pursuing ISIP independent of HSA-FAS

16 32 SHSP objective & recent trajectory 2015 objective: Reduce KA intersection crashes by 5% (2010) 19% 16%

17 33 SHSP objective & recent trajectory Latest raw data suggest these may be out of sync Good opportunity to consider other approaches (e.g., systemic approach)

18 36 ISIP derivation Texas SHSP FHWA support, national resources TxDOT inputs FHWA ISIP process Texas ISIP MPO inputs Local agency inputs

19 37 Overarching goals of Texas ISIP Project 1. Prioritize intersection locations and countermeasures for near-term implementation 2. Strengthen partnerships between TxDOT, MPOs, local governments, and FHWA 3. Identify opportunities for enhancing Texas s data systems to allow for more robust systemic analyses in the future

20 44 Basics Analysis period: January 2010 December 2014 Focused on Texas s 5 largest MPOs: San Antonio (AAMPO) Austin (CAMPO) El Paso (El Paso MPO) Houston (H-GAC) Dallas-Fort Worth (NCTCOG)

21 45 Intersection crashes by severity and year Year Fatal A B C PDO Unknown Total KA %KA ,672 12,760 24,774 69,033 1, ,490 3, % ,609 12,275 24,661 65,753 1, ,664 2, % ,906 13,359 26,086 67,878 1, ,117 3, % ,133 14,757 27,676 79,813 2, ,901 3, % ,240 15,502 29,856 91,812 2, ,256 3, % Subtotal 1,917 14,560 68, , ,289 9, ,428 16, % For 5 MPOs combined

22 47 Systemic analysis concept meets reality Data challenges No single statewide intersection database Traffic volume data not widely available for non Statemaintained routes What is available? MPO TAZ shapefiles area type (rural/urban) TxDOT RHiNo database classification of maintaining agency CRIS database traffic control type as recorded by the reporting officer ESRI Street file node location in GIS

23 Distribution of intersections and KA intersection crashes by area type and traffic control Most significant overrepresentation 51 * *

24 52 Summary & recommendation for TX ISIP KA crashes comprise less than 3% of crashes but 47% of the costs 90% of KA crashes are in urban areas Nearly 50/50 split of KA crashes between State & Local intersections Focus on State & Local Urban Signalized intersections Signalized intersections are significantly overrepresented in terms of proportion of KA crashes vs. proportion of intersections

25 Dallas-Fort Worth area 1 KA crash 59

26 Dallas-Fort Worth area 3 KA crashes 60

27 Potential crash thresholds for systemic treatments 67 Crash Threshold 1 or more KA crash 2 or more KA crashes KA Crashes Intersections Avg. Per Intersection Funding (assuming $45M funding) Number Percent Number Percent 7, % 4, % $9,397 3, % 1, % $32,751 3 or more KA crashes 2, % % $92,593 4 or more KA crashes % % $214,286 For example, more than half of the KA intersection crashes could be addressed by targeting just 29% of the KA intersection crash locations

28 Random Intersection Inventory Identified 100 urban signalized intersections under State or local control that had 2 or more KA crashes during study period No. of intersections from each region was roughly proportional to no. of KA crashes by region Utilized Google Earth and Streetview Maximize information gathered

29 Random intersections Statewide (100) 73

30 83 Roadway attributes 19 of every 20 had some form of lighting fixture 15 of every 16 sites were not noted to be offset and/or skewed

31 92 LT Arrangement by Approach Considering approaches from which left turns were permitted: 70% have exclusive LT lanes or Only 4% have dual LT lanes

32 Traffic Control Count 98 Pedestrian signals 86% Signal head per lane 78% Backplates 54% Automated red light enforcement (cameras) 37% Advance Signal Ahead warning sign 29% Advance street name sign 26% No Turn on Red sign 19% Red light indicator lights 7% Flashing beacons on advance Signal Ahead sign 3% Advance control detection system 2%

33 Inventory to Countermeasures Knowing the estimated level of countermeasure deployment allows the plan to estimate additional deployments of low cost countermeasures Builds on sources including FHWA, TxDOT, research

34 Key Systemic Countermeasures Stop Controlled Intersections Basic set of sign and marking improvements Improve sight distance for speed limits Signalized Intersections Basic set of sign and marking improvements Install one signal head per lane Retime Traffic Signals including change intervals Protected only left turn phases Both Stop Controlled and Signalized Intersections Access management of high volume driveways within feet Delineate or remove fixed objects at intersections 5

35 Backplates with Retroreflective Borders Benefits: Provides visual benefits during both daytime and nighttime conditions Enhanced signal visibility for aging and color vision impaired drivers. May alert drivers to signals during periods of power outages when the signals would otherwise be dark.

36 Low Cost Big Safety Benefit Costs range from $35 for adding reflective tape to existing backplates to $ for replacing the backplates with reflective material already incorporated A 15 percent reduction in all crash types a crash modification factor (CMF) of 0.85 (2005 study by Sayed et al)

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38 Straw Man Outline and Packaging of Safety Countermeasures

39 30 Desired countermeasure characteristics Potential for widespread use Potential impact to severe crashes Easy deployment Low cost Favorable benefit-cost ratio

40 31 Straw Man outline Represents high-level benefit/cost analysis 5-year analysis period is common Comprises estimates of key characteristics: Crash reduction factor Current and potential deployment levels Construction and maintenance costs Potential no. and economic benefits of crashes prevented B/C ratio

41 33 Deployment levels Existing Estimate based on random intersection inventory Potential Considers existing applications and target crash types Estimates will be made on applicability where no inventory could be made (e.g., clearance interval adjustment) No. of potential installations across focus intersections will be estimated

42 35 Potential benefits In terms of anticipated KA crashes prevented Ties back to estimated no. of installations Converts crash savings into cost savings (NSC method) Planning-level B/C ratio estimated

43 4 Systemic approach today & tomorrow Current ISIP effort Applying systemic principles Using available data to derive risk factors, drive focus Initial prioritization zeros in on sites with crash history Future ISIP efforts Opportunities to collect and share additional data attributes across all public roads? Having traffic volume and geometric characteristic data would allow better identification of risk factor combos Prioritization could reach beyond crash intersections to sites having similar combinations of risk factors

44 8 Project next steps Complete planning-level B/C analysis Refine prioritized list of intersections Develop draft ISIP document