LinSig is software by JCT Consultancy which allows traffic engineers to model traffic signals and their effect on traffic capacities and queuing. As well as modelling the effects of traffic signals LinSig also optimises signal timings to reduce delay or increase capacity at a junction or group of interlinked junctions.
LinSig was developed in the UK by Brian Simmonite in the 1980s who went on to set up JCT Consultancy. The software has been updated a number of times during its life.
LinSig was first written in the mid-1980s as a DOS-based tool for analysing and optimising single traffic signal junctions. The use of the software spread mainly by word of mouth within the traffic signals profession becoming widely used by signal engineers. The LinSig traffic modelling was based on standard 'Y' value hand calculations which were widely used at the time for manually calculating traffic signal capacities and delays. This allowed the results of the