Forest Service employees in all program areas routinely work on public roadways while performing their duties. This results in a potentially dangerous work environment not only for the employee but also for the traveling public. Establishing a temporary traffic control (TTC) zone helps mitigate some of the danger, but national statistics indicate that TTC zones still can be deadly. A TTC zone may have many distractions that compete for a driver's attention. These distractions include signs, reduced speeds, flaggers, road closures, and ongoing work activities.

Roadside workers are required by law under 23 Code of Federal Regulations (CFR), Part 655, to wear high-visibility safety apparel when work activities expose them to moving vehicles. There are exceptions to this regulation for firefighters and law enforcement personnel. This guide is intended to help all Forest Service employees understand high-visibility safety apparel requirements and how to use other mitigations for roadside hazards.