However, some additional recommended countermeasures not from the PSCi have been provided in cases where they have the potential to provide a reasonable safety benefit for a corridor and its crash profile. Each proposed countermeasure is accompanied by a timeframe for completion to support project implementation. Crash Modification Factor A Crash Modification Factor (CMF) is provided for each proposed countermeasure. This helps to quantify the potential crash reduction and safety benefit of implementing the proposed countermeasure. CMF is a multiplicative factor that indicates the proportion of crashes that would be expected after implementing a countermeasure. CMFs with a value less than 1.0 indicate an expected decrease in crashes. CMFs greater than 1.0 indicate an expected increase in crashes. CMFs are defined in Part D of the Highway Safety Manual (HSM), accessible online at the CMF Clearinghouse 2 provided by FHWA. TxDOT also provides pedestrian specific CMFs in the “Texas Pedestrian Safety Action Plan (PSAP) Countermeasures Background and Application Methodology 3 ” This study utilizes countermeasures found in the Clearinghouse and TxDOT PSAP. Countermeasure Selection Toolbox Table 3 below provides a CMF for proposed countermeasures and the applicable crash type. It is important to note that a CMF is not always applicable to every crash type. In addition, a few countermeasures do not have an identified CMF, as those countermeasures have not been studied.
Table 3: Countermeasure Toolbox
Crash Modification Factor
Countermeasure
Crash Type
Neighborhood traffic circles
0.18
All
Install Shared-Use Path
0.25
Bike
Install Sidewalks
0.35
Pedestrian
Install Rectangular Rapid Flashing Beacon
0.40
Pedestrian
Install Bike Lanes
0.435
Bike
2 https:/ cmfclearinghouse.fhwa.dot.gov/ 3 https:/ ftp.txdot.gov/pub/txdot/tpp/psap-countermeasures-methodology-memo.pdf
10
Made with FlippingBook - Share PDF online