NACTO released a new guide on how to set speed limits in urban areas. The TL;DR version is:
City Limits outlines a three-method approach to speed limit setting that provides an alternative to percentile-based speed limit setting:
- Setting default speed limits on many streets at once (such as 25 mph on all major streets and 20 mph on all minor streets),
- Designating slow zones in sensitive areas, and
- Setting corridor speed limits on high priority major streets, using a safe speed study, which uses conflict density and activity level to set context-appropriate speed limits.