The cost of new motorway systems is outpacing most government budgets, and space constraints and environmental concerns severely limit options even when they are affordable.
Combine these factors with commuter frustration and the air and noise pollution increases attributable to slow traffic, and the result is a strong demand to use existing streets and motorways more efficiently using traffic flow and control systems.
Consequently, monitoring and managing traffic is much in demand.
In recent years, a growing number of traffic flow and control applications at local, regional, national and international levels have been implemented.
Some of these address congestion by helping drivers choose alternative routes. Others take a more active stance and redirect traffic using such techniques as variable message signs and remote lane controls.