CMF / CRF Details

CMF ID: 10265

Install dynamic speed feedback sign

Description: System consisting of a speed measuring device and a message sign that displays feedback to those drivers who exceed a predetermined threshold. It may be the actual speed, a message such as SLOW DOWN, or activation of a warning device, such as beacons or a curve warning sign

Prior Condition: No dynamic speed feedback sign present

Category: Advanced technology and ITS

Study: Study on Motorcycle Safety in Negotiation with Horizontal Curves in Florida and Development of Crash Modification Factors, Wang et al., 2018

Star Quality Rating: 2 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.78
Adjusted Standard Error:
Unadjusted Standard Error: 0.29
Crash Reduction Factor (CRF)
Value: 22   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 29
Crash Type: Other
Crash Severity: All
Roadway Types: Not specified
Number of Lanes: 2
Road Division Type: Undivided
Speed Limit:
Area Type: Rural
Traffic Volume:
Average Traffic Volume:
Time of Day: All
If countermeasure is intersection-based
Intersection Type:
Intersection Geometry:
Traffic Control:
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used: 2010 to 2017
Municipality: FDOT District 7
State: FL
Country: USA
Type of Methodology Used: Before/after using comparison group
Sample Size (crashes): 22 crashes before, 13 crashes after
Sample Size (sites): 11 sites before, 11 sites after
Sample Size (site-years): 33 site-years before, 33 site-years after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Dec-07-2019
Comments: This CMF applies to lane departure and roadway departure motorcycle crashes on horizontal curves.


The information contained in the Crash Modification Factors (CMF) Clearinghouse is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in the CMF Clearinghouse. The information contained in the CMF Clearinghouse does not constitute a standard, specification, or regulation, nor is it a substitute for sound engineering judgment.