1. N C H R P 17-54 Project PI: Malcolm H. Ray, P.E., PhD RoadSafe LLC mac@roadsafellc.com 207-514-5474 Presented by Team Member: Karen K. Dixon, P.E., PhD Emails: karen.dixon@oregonstate.edu OR k-dixon@tamu.edu

2.  Develop quantitative measures that can be incorporated into the HSM to evaluate the effects of roadside designs and features on the frequency and severity of lane departure crashes.

3.  Literature review  Compared RSAPv3 and the HSM ◦ Encroachment method ◦ Crash-based method ◦ Recommendations for use of both methods  Analyzed sample scenarios ◦ Very different results  Different base conditions  Different units (i.e., single vehicle crashes vs. ROR crashes)  Identified potential data sources and existing CMFs  Interim Report submitted June 6, 2012.

4.  17-54 Interim Report meeting: May 2012  Modifications to RSAPv3: June 2012  Quantitative Measures for HSM: Early 2013  Final Report: Summer 2013

5. Default distribution incudes SVROR crashes (52%) and Overturned (2.5%). No separate SPF for SVRORs (Calculated as a proportion of the total). SVROR is a major crash type but SVROR is only a part of ROR. HSM SPF functional form increases with ADT (generally linear shape). Roadside Hazard Rating is the main measure of roadside condition.

6. Default distribution includes SV crashes (77%). SV are a major crash type for this highway type but ROR crashes are not exactly the same as SV crashes. No separate SPF for SV crashes (Calculated as a proportion of the total). HSM SPF functional form increases with ADT (generally linear shape).

7. A separate SPF for SV crashes by road type. SV overlaps with ROR but is not the same. Different coefficients for the SPF based on road type. Separate SPFs for vehicle-pedestrian and vehicle-bicyclist. Non-linear relationship between ADT and crash frequency.

8. Research just completed Not part of the NCHRP 17-54 Contract

9.  The current SPFs for each road types handle ROR crashes differently. All lump ROR crashes in with something else (i.e., SV or SVROR)  Per Panel Instructions, Project 17-54 will develop new ROR SPFs and CMFs for each road type  Phase II – Rural 2-lane and multilane (current effort)  Phase III – Urban and Suburban

10.  RSAPv3 will continue to be the go-to tool for the analysis of detailed roadside design scenarios and the development of roadside policy.  The new HSM ROR Predictive method and companion CMFs will be the go-to tool for preliminary design and scoping of roadside issues.

11. How should we integrate these new SPFs into an updated HSM? - A new section in each chapter for ROR? - A new chapter on ROR? - How do we handle inconsistencies between the new ROR SPFs and the existing ones? What about double counting?