Which statement best describes the relationship between the Highway Safety Manual CMFs and the CMF Clearinghouse?

• A. The Highway Safety Manual contains a limited number of high-quality CMFs; these CMFs are published, along with many others, in the CMF Clearinghouse.
• B. The Clearinghouse is the primary source of all CMFs, replacing the HSM content.
• C. CMFs in the Clearinghouse are not compatible with those in the HSM.
• D. The Clearinghouse lists CMFs only for rural roads.

Answer: (A)

At the heart of this is how CMFs are organized and accessed. The Highway Safety Manual presents a curated set of high-quality CMFs that are well documented and suitable for use in HSM-based analysis. The CMF Clearinghouse, on the other hand, is a broader repository that collects CMFs from multiple sources, including those highlighted in the HSM, and makes many more CMFs available to practitioners. It does not replace the HSM; instead it complements it by expanding the pool of CMFs you can reference. So the best description is that the HSM provides a limited, high-quality core of CMFs, and those same CMFs are published in the Clearinghouse along with many additional ones.