Compliance Effective Date For High Visibility Clothing on Federal Highways
As of Nov. 24, 2008, all workers within the right of way of a federal-aid highway are required to wear high visibility clothing that meets the performance requirements of ANSI/ISEA 107-2004 Class 2 or Class 3 ANSI/ISEA 207-2006 (public safety vests). The Federal Highway Administration published the final rule regarding high visibility clothing as Part 634 of Title 23 (23 CFR part 634) Code of Federal Regulations to reduce the likelihood of worker fatalities and injuries caused by motor vehicles and construction equipment on federal-aid highways.

All workers within the right of way of a federal-aid highway exposed either to traffic or construction equipment must wear high-visibility clothing. This rule applies to people on foot whose duties place them within the right of way of a federal-aid highway. This includes construction, maintenance, survey and utility crews as well as first responders and law enforcement personnel responding to incidents or traffic-related issues within the right of way of a federal-aid highway.

OSHA Update, October 20, 2009
WASHINGTON - High-visibility clothing is required safety attire for highway and road construction workers according to a new letter of interpretation recently released by the Occupational Safety and Health Administration. OSHA is issuing a new letter stating that all highway and road construction workers must wear high visibility clothiing regardless of whether the MUTCD requires them. OSHA considers road and construction traffic a well-recognized hazard to highway/road construction workers. Bureau of Labor Statistics reinforced the need for using high visibility clothing when data from 2003 to 2007 showed there were 425 road construction work zone fatalities.