As daylight diminishes during the fall and winter months, decreased visibility can be very dangerous for workers in numerous occupations, particularly construction. 

The end of daylight saving often leaves many of us feeling fatigued, and this can pose safety risks. Studies suggest it takes people who work traditional hours several days to fully adjust their sleep schedule after the time change. 

The safety plan for a darkened worksite should include an analysis of potential hazards, such as blind spots, tripping or falling hazards and dangerous equipment. 

To help prevent accidents in low-light or dark conditions, consider the following: 

• As visibility decreases, adjust accordingly. Vehicle operators should reduce speed and workers should exercise extra caution. 
• It’s not enough to wear bright colored clothing; you need approved high-visibility apparel. 
• If the use of large machinery is required, several workers should be assigned as spotters to check all surrounding areas and warn other workers and/or machine operators. 
• Workers and equipment should be separated as much as possible. The safest routes to walk or drive equipment should be clearly identified. 
• Lighting helps increase visibility. If workers do not have enough visibility to work safely, they should not be performing their jobs. This applies not only to night shifts but early mornings as well. 
• Bright lights on darkened worksites can create glare that inhibits visibility. They need to be positioned correctly to ensure the best visibility. 
• All vehicles and machinery have blind spots, but when visibility is reduced they can be much larger. 

Road work can be especially hazardous
in low-light conditions. 

One reason road construction is done at night is to avoid traffic congestion and related problems encountered during daylight hours. However, it also carries the risk that motorists are less attentive and drive at higher speeds. In addition, more drivers impaired by alcohol or drugs are involved in work zone accidents at night. 

Here are suggested practices
to help minimize risks: 

• Use portable, changeable message signs to encourage speed compliance. 
• Deploy what is termed positive protection, a portable concrete or plastic barrier or other device that minimizes vehicle damage but prevents intrusion into the work zone. 
• Wear a hard hat and clothing that has retroreflective material visible from all sides and from a minimum distance of 300 meters (1,000 feet). 
• Where positive protection is not available, use retroreflective material on all drums and cones and, where possible, use drums instead of cones. When using cones, stack two together or put weights on them to keep them in place. Make certain all signs and traffic channeling devices are maintained in place and in good condition. 
• A full-time traffic control person should monitor the work zone several times a night and review all aspects of project visibility. The person also must make sure signage does not send confusing, mixed messages. 
• Reduce the glare from work lighting. To avoid blinding motorists passing the work zone, position and align lights to keep them aimed toward the work area and not toward traffic. Glare is also a problem for motorist visibility and is caused by not extending light poles to the proper height or by not aiming the light downward to limit illumination to the work zone.