To be implemented within Europe, Vehicle Restraint Systems (VRS) have to meet the requirements of the European Standard EN 1317. The systems have to undergo crash tests, whose parameters and acceptance criteria are defined by the norm. Depending on the test results, the systems are divided into performance classes. Each type of VRS is evaluated in an individual part of the EN 1317.
The Manual for Assessing Safety Hardware presents uniform guidelines for crash testing permanent and temporary highway safety features and recommends evaluation criteria to assess test results. The crash performance is judged on structural adequacy, occupant risk, and vehicle trajectory.
The Manual on Uniform Traffic Control Devices (MUTCD) describes basic principles for evaluating traffic control devices for Streets and Highways. The MUTCD, published by the Federal Highway Administration (FHWA), standardizes traffic control devices throughout the country to ensure that they mean the same to, and require the same actions by, all motorists anywhere in the country.
On July 27, 1997, the FHWA's Office of Engineering issued a guidance memo mandating that all work zone devices, used on the National Highway System (NHS), be crash tested to NCHRP 350 requirements. This memo went on to divide many of these devices into four (4) categories, with each having their own level of testing requirements and compliance dates.
Warning lines shall consist of ropes, wires, or chains, and supporting stanchions. A warning line is used 15' or more from the roofs edge. The rope, wire, or chain shall be flagged at not more than 6-foot (1.8 m) intervals with high-visibility material. The TrafFix Devices Roof Edge Delineator warning line system meets or exceeds the requirements put forth in 1926.502(f)(2).