Practice question

What is the primary difference between a safety performance function (SPF) and a crash modification factor (CMF)?

SPFs apply only to intersections while CMFs apply only to segments
An SPF predicts the expected number of crashes for a base condition, while a CMF estimates the change in crashes from a specific treatment or feature
SPFs are qualitative while CMFs are quantitative
There is no difference; they are the same concept

Answer: B — An SPF predicts the expected number of crashes for a base condition, while a CMF estimates the change in crashes from a specific treatment or feature

The correct answer is shown above. Try the full quiz for additional practice.