German approach for off-line optimization of traffic signals within networks.

In this article, the use of SIGMA (SIGnalplan MAnagement) software to optimize fixed time traffic signals, in a trial on a road network in Darmstadt, West Germany is outlined. The software contained modules for traffic flow, optimization and evaluation. The held trial consisted of a before and after study, carried out during the morning peak hours, at 30 junctions in the town. For the total network delay to private vehicles decreased by 6%, on the priority routes, journey speed increased by 17% and delay decreased by 3%.