How can road curves be analyzed to improve motorcycle safety? Eva M. Shipp, Ph.D. Amber B. Trueblood, DrPH

Project Team Eva Shipp, Ph.D. Amber Trueblood, Dr.P.H. Marcie Perez Chris Bratlien Myunghoon Ko, Ph.D. Ashesh Pant Lingtao Wu, Ph.D. Robert Wunderlich, P.E.

Curve Analysis Background Highest crash risk and highest severity level for motorcycle crashes [Adinegoro, Haworth & Debnath, 2015; Blackman & Haworth, 2013] MC riders more likely to crash on curves MSF 100 Naturalistic Crash Study: 55% of single MC crashes on curves [Williams et al, unpub]

Previous Texas Study 25% of on-system fatal & incapacitating MC crashes Likely underreported

Crashes on Curves in Texas (>1650 riders/year) ≈150 fatalities/year >450 serious injuries/year

MCs vs. Non-MCs on Curves in Texas Riders who crash on curves: about ten times as likely to die compared to non-MCs who crash on curves.

MC crashes in Texas Riders who crash on curves: about twice as likely to die compared to riders crashing on straight roadways.

Why curves? Less stable that cars/trucks Limited sight-distance Curve radius Speed variation Negotiation maneuvers “Curve appeal”

Identifying Factors and Trends to Improve Motorcycle Safety in Texas Builds on FY 16 project Motorcycle Crash Database update Analysis New method for analyzing curve-related crashes

Identifying Factors and Trends to Improve Motorcycle Safety in Texas Project tasks Data analysis plan Focus groups Surveys Motorcycle Crash Analysis Output 4 motorcycle factsheets 1 final report

Curve Analysis Method Used the 2016 Texas Roadway Inventory Data to identify curves.

Curve Analysis Method Mapped the Latitude and Longitude Points from the Roadway Inventory data. Used to create segments.

“The Three Sisters” 839 data points from Camp Wood, TX to Vanderpool, TX

Curve Analysis Method 3. Developed pilot online GIS-based tool to identify curves.

Curve Analysis Method Segments individually pass a set of tests activated by the user to be identified as a Curve Tests Used: Minimum Deflection Angle Minim Ratio of a Segment’s Deflection Angle to its Length

Curve Analysis Method-To Do 4. Finalize online GIS-based tool developed to identify curves. Fine-Tune the tool

Curve Analysis Method-To Do Flag curve-related crashes from 2010-2017 using developed online GIS-based tool.

Curve Analysis Method-To Do Analyze crashes flagged as curve-related to identify crash factors related to entering and exiting a curve. Compare the tool’s flagged crashes with TxDOT CRIS flag to identify potential underreporting.

Questions? Eva Shipp, Ph.D. (979) 458-4398 E-Shipp@tti.tamu.edu Amber Trueblood, DrPH (979) 845-7606 A-Trueblood@tti.tamu.edu

References Adinegoro, Y., Haworth, N., & Debnath, A. K. (2015). Characteristics of road factors in multi and single vehicle motorcycle crashes in Queensland. Blackman, R. A., & Haworth, N. L. (2013). Comparison of moped, scooter and motorcycle crash risk and crash severity. Accident Analysis & Prevention, 57, 1-9. TTI. 2016. Extract from the Texas Department of Transportation Crash Records Information System. TTI. 2016. Comprehensive Analysis of Motorcycle Crashes in Texas: A Multi-Year Snapshot. Report Number: 2016-TTI-G-1YG-0029. Williams, McLaughlin, Atwood, and Buche: Factors that Increase and Decrease Motorcyclist Crash Risk (unpublished report).