SUMO Simulation. Detecting high Traffic and reducing the speed limit

Question

I am learning SUMO from beggining, I read and learned most of tutorials from: http://sumo.dlr.de/wiki/Tutorials . What I want to do now is to make Cars slow down when there is a Traffic on a Road. I only know how to change the speed limit after a certain Time from here: http://sumo.dlr.de/wiki/Simulation/Variable_Speed_Signs . Do you know how can I change the speed limit when there is Traffic? I think that changing the value of speed Signs is the best Idea here, but I don't how do it.

Answer 1

There is no such thing as event triggered speed signs in SUMO, so you probably need to do that via TraCI. The easiest way is probably to start with the TraCI tutorial for trafficlights and then use functions like traci.edge.getLastStepOccupancy to find out whether vehicles are on the edge in question and then traci.edge.setMaxSpeed to set a new speed.