Texas Intersection Safety Implementation Plan Workshop JUNE 2, 2016
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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Texas: 802 Intersection Fatalities (2014) 12
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
Texas SHSP ‐ Intersection 15
Texas SHSP ‐ Pedestrians 16
Approaches to Saving Lives and Preventing Serious Injuries Traditional Systemic Comprehensive Policy Culture 17
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 10 ‐ 20 per year in a average size state – By itself, negligible impact on reducing statewide fatalities Traditional Systemic Comprehensive Policy Culture 18 18
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) Traditional – Plan can be tailored to available resources Systemic – Can also include a Corridor/Community 3E component Comprehensive Policy Culture 19
Basic Approach for Intersections 20
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
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
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.” http://safety.fhwa.dot.gov/systemic 23
FAS-INT : Systemic Intersection Safety Plans From 2008-Current DC PR *Multiple ISIPs in TX FLH Intersection Safety State considering or pursuing Implementation Plan (ISIP) ISIP independent of HSA-FAS completed through HSA-FAS
32 SHSP objective & recent trajectory 2015 objective: Reduce KA intersection crashes by 5% (2010) 19% 16%
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)
36 ISIP derivation • Texas SHSP • FHWA support, national resources Texas ISIP FHWA ISIP process • TxDOT inputs • MPO inputs • Local agency inputs
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
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)
45 Intersection crashes by severity and year Year Fatal A B C PDO Unknown Total KA %KA 2010 330 2,672 12,760 24,774 69,033 1,921 111,490 3,002 2.69% 2011 372 2,609 12,275 24,661 65,753 1,994 107,664 2,981 2.77% 2012 428 2,906 13,359 26,086 67,878 1,460 112,117 3,334 2.97% 2013 372 3,133 14,757 27,676 79,813 2,150 127,901 3,505 2.74% 2014 415 3,240 15,502 29,856 91,812 2,431 143,256 3,655 2.55% Subtotal 1,917 14,560 68,653 133,053 374,289 9,956 602,428 16,477 2.74% For 5 MPOs combined
47 Systemic analysis | concept meets reality Data challenges – No single statewide intersection database – Traffic volume data not widely available for non State- maintained 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
51 Distribution of intersections and KA intersection crashes by area type and traffic control Most significant overrepresentation * *
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 Focus on State & Local Urban • Nearly 50/50 split of KA crashes Signalized between State & Local intersections intersections • Signalized intersections are significantly overrepresented in terms of proportion of KA crashes vs. proportion of intersections
59 Dallas-Fort Worth area | ≥ 1 KA crash
60 Dallas-Fort Worth area | ≥ 3 KA crashes
67 Potential crash thresholds for systemic treatments KA Crashes Intersections Crash Avg. Per ‐ Intersection Funding Threshold (assuming $45M funding) Number Percent Number Percent 1 or more KA 7,212 100.0% 4,789 100.0% $9,397 crash 2 or more KA 3,797 52.6% 1,374 28.7% $32,751 crashes 3 or more KA 2,021 28.0% 486 10.1% $92,593 crashes 4 or more KA 1178 16.3% 210 4.4% $214,286 crashes • For example, more than half of the KA intersection crashes could be addressed by targeting just 29% of the KA intersection crash locations
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
73 Random intersections | Statewide (100)
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
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
98 Traffic Control Count 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%
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
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 50 ‐ 100 feet – Delineate or remove fixed objects at intersections 5
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 .
Low Cost – Big Safety Benefit Costs range from $35 for adding reflective tape to existing A 15 percent backplates to $56 ‐ 110 for reduction in all replacing the backplates with crash types—a reflective material already crash modification incorporated factor (CMF) of 0.85 (2005 study by Sayed et al)
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Straw Man Outline and Packaging of Safety Countermeasures
30 Desired countermeasure characteristics Potential for widespread use Potential impact to severe crashes Easy deployment Low cost Favorable benefit-cost ratio
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