Safety, Energy and Environmental Evaluation of Flashing Operation at Traffic Signals at Off-Peak Hours

Safety, energy and environmental effects were evaluated to determine the level of control at an intersection. The control strategy examined is the cessation of regular signals during low traffic volumes, and the substitution of a flashing amber operation. A flashing operation comparative conflict study of the two types of signal operations showed that for low traffic volumes (up to 600 veh/h), a flashing operation does not bring about a deterioration of the safety level at the intersection. A quantitative evaluation of the energy consumption and the additional air pollution caused by each type of control strategy led to recommendations to include energy and environmental considerations during the decision-making process on the level of signing and priorities. This would bring about a better balance of intersection control and, by lowering the levels of air pollution and noise, create a more wholesome environment