Road Safety Workshop for Identifying Treatment Locations

1. NC Local Safety Partnership Identifying Potential Treatment Locations

2. Workshop Roadmap  

3. Module Objective • Learn about different types of local and state data sources • Understand the basics of network screening • Incorporate road safety audits as a tool for assessing locations

4. Module 3 – Identifying Treatment Locations Local data sources

5. Local Data Sources • Local database of police crash reports • Pattern detection through regular data management and maintenance • Staff observations • Problem areas identified by staff during regular reviews

6. Local Data Sources • Road safety teams • Review problem corridors based on crashes or complaints

7. Local Data Sources • Public or media inquiries • Agency policy may require the investigation of any sites identified in this way Example article from Florida newspaper

8. Local Data Sources • Plan review • New developments and the subsequent changes in traffic patterns may trigger the review of surrounding streets and intersections for possible safety improvements • Past locations • Monitoring of past locations that were treated can be useful to identify both successes and failures; the failures may warrant additional efforts to select a different intervention

9. Module 3 – Identifying Treatment Locations State data sources

10. State Data Sources • Traffic Engineering Accident Analysis System (TEAAS) • Periodic reports can be generated from TEAAS to develop lists of intersections or other locations that meet a specific threshold for investigation; W-S produces such reports for intersections with 5 or more crashes over a 3-year period • Example: City-wide reports

11. State Data Sources • NCDOT Lists • The Traffic Safety Unit (TSU) within NCDOT, through their statewide analysis efforts, may provide lists of locations identified as high-crash locations • Contacts • Brian Mayhew (919-773-2886, bmayhew@ncdot.gov) • Stephen Lowry (919-773-2892, slowry@ncdot.gov)

12. Module 3 – Identifying Treatment Locations USING DATA TO IDENTIFY TREATMENT LOCATIONS

13. Process • Process for identifying treatment locations: • Establish focus • Identify reference populations • Select performance measures • Select screening methods • Screen and evaluation results

14. Network Screening • Step 1 – Establish Focus • Network screening can be conducted on one or both of the following: • Overall Crash Reduction: An agency wishes to identify and rank sites where improvements have potential to reduce the number of crashes • Policy Implementation: An agency is implementing a particular safety-based strategy or policy. To do so, they evaluate the network to identify sites with a particular crash type or severity level

15. Network Screening • Step 2 – Identify Reference Population • Identify network elements to be screened • Intersections • Roadway segments • Organize by reference population

16. Network Screening • Step 3 – Select Performance Measures • Number of crashes • Crash severity • Critical crash rate • Property damage

17. Network Screening • Step 4 – Select Screening Method • Different types of screening methods for segments, intersections, and corridors: • Segments: Sliding window, peak searching • Intersections: Simple ranking • Corridors: Sliding window, peak searching, simple ranking

18. Network Screening • Step 5 – Screen/Evaluate Results • Calculate performance measures for each segment or intersection • Rank order

19. Module 3 – Identifying Treatment Locations Road safety audits

20. Road Safety Audits • Road Safety Audits are intended to address these questions: • What elements of the road may present a safety concern: to what extent, to which road users, and under what circumstances? • What opportunities exist to eliminate or mitigate identified safety concerns?

21. Road Safety Audits • RSA Process • Performed by a team independent of the project • Performed by a multi-disciplinary team • Considers all potential road users • Accounting for road user capabilities and limitations is an essential element of an RSA • Always generates a formal RSA report, which is an essential element of an RSA

22. Module 3 – Identifying Treatment Locations OTHER CONSIDERATIONS

23. Other Considerations • Further diagnostics • Simply knowing there is a higher than normal number of crashes may not be enough information to make a full assessment. Crash patterns, for example, may lend more insight and will be covered in the next module. • Treatability • Is there a solution (low-cost) for the problem? • Feasibility • Funding level available for treatments? (More to be covered in Module 7) • Prioritizing among multiple issues? (More to be covered in Module 5)

24. Take Away Messages • Numerous local data sources to consider • Resources available from State to provide additional data • Network screening can help identify locations based on data trends • Field review and audits are a critical step