The United States Department of Transportation (DOT) is the federal department of the U.S. government that establishes laws regarding transportation. On any federally funded highway project, workers must adhere to Chapter 23 Part 634 of the Code of Federal Regulations (CFR), which defines the requirements of high visibility safety apparel. Safety vest laws are intended to reduce road worker fatalities caused by motor vehicles.
Title 23 Part 634.2 of the CFR describes what types of workers must wear safety vests on a highway or federally funded road project. Any worker whose duties place him in a situation where he is on foot in the right of way on a federally funded highway must wear safety vests. This includes construction and maintenance workers, survey or utility workers and first responders to emergencies. Police officers who are investigating crashes, closing lanes or directing traffic must wear safety vests during their duties, according to the Department of Transportation. As of November 24, 2008, all workers on state and local roads must comply with federal regulations regarding safety vests.
The Federal Highway Administration (FHWA), a division of the DOT, requires construction workers in highway work areas to wear at least a Class 2 safety vest. Safety vest standards are provided independently by the American National Standards Institute (ANSI). The ANSI defines Class 2 garments as meant for workers in traffic zones that exceed 25 miles per hour. ANSI recommends Class 3 garments for workers who are working on roadways where vehicle speed exceeds 50 miles per hour. Class 3 garments offer the highest level of visibility in all types of weather conditions.
ANSI 107 regulations require Class 2 safety vests to have a minimum of 775 square inches of fabric, which must be fluorescent, and 201 inches of reflective strips placed around the vest. Fabric may be fluorescent and yellow-green, red or orange-red. Reflective strips must be at least 1.375 inches. A Class 3 safety vest must have 1240 square inches of fluorescent background and 310 square inches of reflective strips. Reflective strips must measure a level 1 or level 2 on a photometric scale, which determines how well the strips reflect vehicle lights.
The natural environment should determine the appropriate choice of coloring. In an urban setting, red may be less conspicuous than fluorescent yellow. No matter what the weather situation, the Federal Highway Administration requires safety vests to be worn. Workers must wear safety vests both day and night, as long as they are working on a project.