State Safety Data Systems

Q: What are the requirements for collecting Average Annual Daily Traffic (AADT)?

A: The HSIP Final Rule does not specify how agencies obtain AADTs. Agencies may make their own determination about how they obtain AADTs, whether by actual count or by some estimation method (e.g., assignment-based similarities in location and function) or some combination of the two. We recommend that agencies apply or adapt current traffic monitoring approaches, as documented in FHWA's Traffic Monitoring Guide, to obtain AADT estimates for roadways covered by the HSIP Final Rule that are not part of their current traffic monitoring effort.

Q: What intersections require the collection of MIRE FDE?

A: All intersections with at least one of the roads functionally classified as non-local require the collection of MIRE FDE. This would include inventorying non-local/non-local intersections as well as non-local/local intersection. Only local/local intersections do not require MIRE FDE.