PIARC T.C. C2.1 & C2.3 Comparison of National

Road Safety Policies & Plans

Crash Analysis/Problem Definition&

Time of Return Methodology

October 2008

Larry E. TibbitsMichigan Department of Transportation

Kuala Lumpur, Malaysia

Crash Information in Michigan to Define Problems Areas

Crash Incident Documentation/ Processing

• Crash report is completed by Law Enforcement Officer

• All crashes involving injuries, and most property damage crashes must be reported

• Statewide standard crash report form (next slides)

• Paper and electronic version of crash report form

• All reports processed by Michigan State Police

• All reported crashes are located on linear and GIS based referencing systems

Michigan Crash Report Form (front)

Michigan Crash Report Form (back)

Crash Processing

• Scan the form and create electronic image

• Use intelligent character recognition of written information

• Validate text data

• Attach location information

• Post crash data to crash data warehouse

Safety Analysis to DefineProblem Areas

• Michigan Strategic Highway Safety Plan – data driven identification of 12 safety focus areas• Identification of Engineering, Enforcement,

Education, and Emergency Medical Services treatments

• Highway Safety Improvement Program (HSIP)• Identify high crash locations for treatment• 5% Report – worst 5% of locations statewide• Post safety treatment evaluations

• Call for Safety Projects

Safety Analysis to DefineProblem Areas

Of the 12 SHSP focus areas, three are predominately addressed by the HSIP:

• Intersection safety

• Pedestrian and Bicycle Safety

• Lane Departure

Safety Analysis to DefineProblem Areas

These locations are identified through:

• High crash list• 5% Report• Fatality and serious Region wide maps• Project Required Safety Reviews• Customer concerns• Pavement friction analyses

Call for Projects Safety ProjectsFY 2011

Region Number of Fatalities and Serious Injuries

(2004-2006)

Percentage of Fatalities and Serious Injuries

(2004-2006)

FY 2011 SafetyTarget

Superior 820 7.12% $1.00 M

North 1,172 10.18% $1.50 M

Grand 1,628 14.14% $1.95 M

Bay 1,463 12.70% $2.04 M

Southwest 1,426 12.38% $1.82 M

University 1,766 15.33% $2.60 M

Metro 3,242 28.15% $4.69 M

Discretionary $2.00 M

SWA $1.40 M

Totals 11,517 100% $19.00 M

Time of Return (TOR)

• It is one type of cost benefit tool• Estimates benefits (reducing

crashes/injuries/deaths)• Output: the number of years required

to recover the safety investment• Based upon Roy Jorgensen’s report

on Highway Safety Improvement Criteria

Why Use TOR

• Federal Highway Safety Improvement Program requires that we invest safety dollars where they are needed most – where we get the greatest return

• Helps prioritize competing safety projects

• Verifies how the safety fix matches the demonstrated safety problem

Crash Data used in TOR

• Crash type• Number of crashes• Property damage only + minor injury (B, C)• Number of A injuries or number killed

(people)• Each incident is one crash

TOR Components

• Estimated costs of deaths and injuries from U.S. National Safety Council (http://www.nsc.org/)

• Estimated benefits resulting from reducing crashes

• Traffic volumes• Reduction in fatalities and A injuries

combined• Reduction in minor (no A injuries or

fatalities) crashes

TOR Components

• Q factor to blend the impact of fatalities and A injuries

• Estimated project costs• Number of years of crash data used

(3-5)• Area Factor - Urban, rural, and

between

The Calculation

• Roy Jorgensen's Formula BTOTAL = ADTa/ADTbx/ (QxR1+(PDOCOSTxR2)) • BTOTAL = Total benefit in dollars

over years used• ADTa = Average traffic volume after

the improvement (assumed)• ADTb = Average traffic volume

before the improvement

The Calculation (Continued)

• R1 = Reduction in fatalities and A-injuries combined

• R2 = Reduction in minor (no A-injuries or fatalities) crashes

• Q = [FATCOST+((I/FxINJCOST]/1+(I/F]

Summary

• Michigan a has sound crash records system in place

• Crash data, along with other safety data allow for problem identification, selection of treatments, and evaluation of implemented safety treatments

• Crash data is essential to Michigan identifying strategic highway safety goals and monitoring safety performance

• http://www.michigan.gov/tands