Road Safety Professional (RSP) Level 1 Practice Exam

Crash Modification Factors quantify how a safety countermeasure is expected to change crash frequency, and the CMF Clearinghouse is the public database that collects these factors from many studies, with notes on context, methods, and quality. This combination makes it the best place to find high-quality CMFs published alongside many others, so you can compare options across different situations. The Highway Safety Manual uses CMFs as part of its guidance but isn’t the central repository of CMFs. The National Transportation Safety Board focuses on accident investigations and safety findings, not a CMF database. The Federal Highway Administration provides guidance and oversight but does not serve as the primary CMF collection.