Driver Comprehension of Lane Reduction Signage: Alternatives to the MUTCD W4-2 for Work Zones

Many work zones require lane closures, and road users need to be notified of these closures through appropriate upstream signage. Inadequate driver comprehension of the existing U.S. standard lane reduction sign (MUTCD W4-2) and similar signs used internationally has been reported by practitioners and repeatedly affirmed in the research literature. The W4-2 sign is also unsuitable for signing interior lane closures on roadways with three or more lanes. To address this concern, driver comprehension of several alternative sign faces was tested using the ANSI Z535.3 survey process. The results suggest that an Upward Drop Arrow design is a promising alternative to the existing W4-2 sign for sites where two upstream lanes are reduced to one lane in the work zone. One-arrow-per-lane signs developed as Americanized versions of the Vienna Convention G12a sign template were found to be a promising option for interior lane closures on multi-lane roadway segments.