The public roads and highways are designed to allow people to travel safely to their destinations. Occasionally, construction or maintenance work may temporarily block or reduce access to the full use of these roads. In cases where workers must control traffic flow and perform work in close proximity to road traffic, procedures must be followed to maintain the highest degree of safety to the worker as well as drivers and pedestrians. Work that must be done on or near roads presents hazards to workers, drivers, pedestrians, equipment and property. The possible number of fatalities, serious injuries, and large amounts of property damage can be greatly reduced by instituting and complying safety procedures for road work. Each work zone is unique and can present several challenges to establishing a safe work zone. Rolling hills and curved roads reduce distance visibility and may require adjustments to the usual procedures. Other adjustments to the standard work zone procedures may also be required such as several close intersections, darkness, rainy or foggy conditions, very heavy traffic, or even the time of year.