The Federal Highway Administration (FHWA), U.S. Department of Transportation (DOT) has released minimum levels of retroreflectivity for pavement markings. These rules are designed to keep the roads navigable for an older driving population with a greater need for visible markings.
FHWA released a final rule to update the Manual on Uniform Traffic Control Devices (MUTCD) to provide standards, guidance, options, and supporting information on September 6th. This final rule establishes minimum retroreflectivity levels for longitudinal pavement markings on all roads open to public travel with speed limits of 35 mph or greater. The final rule requires applicable agencies or officials to implement a method for maintaining pavement marking retroreflectivity at or above minimum levels, providing a 4-year compliance date for implementing the method. County’s must adopt a method (plan and procedure) for maintaining pavement marking retroreflectivity by September 2026.
The Final rule provides exemptions for agencies on roads where illumination or low volumes make minimum retroreflectivity a non-issue. Roads with less than 6000 Average Daily Travel (ADT), curb markings, parking space markings, and shared-use path markings are excluded from the rule. The Final rule also provides exemptions for agencies for special circumstances including: road degradation, planned resurfacing, snow maintenance activities, and Unanticipated events such as equipment breakdowns, material shortages, and contracting problems. A full list of exceptions can be found in Paragraph 5 (Page 8 and 9 of the Final Rule).
Standard minimum levels of retroreflectivity is as follows: Except as provided in Paragraph 5, a method designed to maintain retroreflectivity at or above 50 mcd/m2/lx (means millicandelas per square meter per lux) under dry conditions shall be used for longitudinal markings on roadways with speed limits of 35 mph or greater.
Guidance on minimum levels of retroreflectivity is as follows: Except as provided in Paragraph 5, a method designed to maintain retroreflectivity at or above 100 mcd/m2/lx under dry conditions should be used for longitudinal markings on roadways with limits of 70 mph or greater. Guidances are only recommendations and are not required.
Retroreflectivity levels for pavement markings are measured with an entrance angle of 88.76 degrees and an observation angle of 1.05 degrees. This geometry is also referred to as 30-meter geometry.
Additional Resources on the final rule as well as method for maintaining pavement marking retroreflectivity can be found below.