Traffic load is highly dependent on parameters such as time, day,
season, weather and unpredictable situations such as accidents, special
events or construction activities. If these parameters are not taken into
account, the traffic control system will create bottlenecks and delays. A
traffic control system that solves these problems by continuously
sensing and monitoring traffic conditions and adjusting the timing of
traffic lights according to the actual traffic load is called an intelligent
traffic control system.
Traffic control systems may also be classified as saturated or
unsaturated, depending on whether they were designed for a
saturated or unsaturated network. In an unsaturated network, it is
desired to minimize the mean delay of drivers, while in a saturated
network it is desired to serve as many drivers as possible, or in other
words, to maximize traffic capacity of the intersection. The problem
of capacity maximization is the same as the queue minimization
problem