Putting Together a Safety Program Kevin J. Haas, P.E.—Traffic Investigations Engineer Oregon Department of Transportation Traffic—Roadway Section (Salem, OR) Presented at Roadway Safety for Local Agencies Workshop February 19, 2010 (Corvallis, OR)

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, Overview Good safety program guidance is hard to find AASHTO Highway Safety Manual Relationship between crashes & exposure Safety Performance Functions Understanding & applying the HSM Safety data gathering tools Closing/Q & A –Where can you find help in developing your local agency’s safety program?

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, A history lesson… Good guidance publications for developing road safety programs are hard to find –FHWA  Manual on Uniform Traffic Control Devices (MUTCD) –AASHTO  A Policy on Geometric Design of Highways and Streets (The “Green Book”) –TRB  Highway Capacity Manual (HCM)

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, TRB identifies need for safety manual 1999 –TRB concerned about lack of highway safety information in the Highway Capacity Manual (HCM) 2003 –TRB Task Force formed to develop stand alone safety manual 2010 –1 st Edition of the AASHTO Highway Safety Manual (HSM) scheduled to be released S A F E T Y

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, What is the HSM?

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, What does this mean for my local agency? Examined in reference to compliance with standards, warrants, guidelines and sanctioned design procedures The expected or actual crash frequency and severity for a highway or roadway *Ezra Hauer, ITE Traffic Safety Toolbox Introduction, 1999

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, How can the HSM help me develop a safety program for my local agency? Can you answer this question? Is this road “safe” or “unsafe”? What about this road?

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, The relationship is typically not linear! HSM uses regression equations called Safety Performance Functions (SPF) to explain this relationship SPFs can predict the average number of crashes per year for an intersection or highway segment as a function of traffic volume Understanding the relationship between crashes & exposure

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, How would I develop a SPF for my local road system? Plot crashes over a number of years on roads with similar characteristics Variability (randomness) of crashes handled by grouping crashes with similar volumes

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, How can SPFs help me build a safety policy or program for my local agency? Sample SPF for all 2- Lane Rural County Roads in Oregon Data point representing existing conditions for upcoming project Potential local agency policy requires safety improvements to bring location back in line with or below SPF curve Expected improvement from application of Crash Modification Factors (CMF)

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, Why should I use the HSM as the basis for my local agency safety program? The HSM does not establish a legal standard of care nor does it create a duty to the public.

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, The HSM is not a replacement for… Manual on Uniform Traffic Control Devices (MUTCD) Your agency’s Policy or Traffic Manual AASHTO “Green Book” (A Policy on Geometric Design of Highways and Streets)

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, The HSM represents a new way of thinking… Old (Reactive) Descriptive analyses Historical summary of crash occurrence, type and/or severity at a site New (Proactive) Quantitative predictive analyses Future expected number of crashes based on the geometric and operational characteristics at a site

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, What do I need to start using the HSM to build my safety program? Crash data –Crash location –Date/time –Crash severity –Collision type –Basic roadway & vehicle information Facility data –Roadway classification –Number of lanes & width –Shoulder presence & width –Intersection data (i.e. road names, area type, traffic control, lane configurations) Traffic volume data –Annual Average Daily Traffic (AADT) –Intersections  Total Entering Vehicles (TEV)

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, What are some examples of easily accessible tools to help collect some of my safety data? Video Logs Roadside Inventories Google Earth/Maps Raw crash data & crash reports

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, The HSM is huge! How can I possibly understand all of it? Take baby steps! Focus on parts of the HSM that are easily implemented like CMFs

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, Crash Modification Factors (CMF) Quantify the expected change in crashes at a site caused by implementing a particular treatment –Also known by other terms such as countermeasures or Crash Reduction Factors (CRF) Comparison usually involves evaluating safety conditions with or without a particular treatment, or safety conditions with one treatment versus another treatment

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, Application of CMFs Estimate the expected safety performance with the treatment in place Some typical examples of CMFs include: –I–Illuminating an unlighted road segment –P–Paving gravel shoulders –S–Signalizing a stop-controlled intersection –D–Deciding to use a 240-foot radius for a horizontal curve instead of a 180-foot radius –C–Choosing a signal cycle time of 70 seconds instead of 80 seconds

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, Reliability of CMFs CMFs must be applied according to the conditions associated with each CMF (i.e. road type, traffic volume, crash severity, etc.) Some CMFs include a standard error which indicate variability in achieving expected results

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, How is ODOT using the latest tools & methods in the HSM to transform our safety program? Predictive analysis methods require data, data, & more data! ODOT is working on enhancing our data through our Asset Management Program Major data deficiencies in roadside character & cross-street intersection data

Putting Together a Safety Program—Kevin Haas, P.E.—ODOT Traffic-Roadway Section February 19, Where can I get help in developing my local agency’s safety program? Contact OTREC or the Kiewit Center at OSU Refer to the HSM when it is published in 2010 by AASHTO highwaysafetymanual.org