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

2. 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.

3. 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]

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

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

6. 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.

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

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

9. 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

10. 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

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

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

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

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

15. 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

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

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

19. 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.

20. Questions?
Eva Shipp, Ph.D. (979) Amber Trueblood, DrPH (979)

21. 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 Extract from the Texas Department of Transportation Crash Records Information System.
TTI 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).