Scaling traffic density in SUMO

Question

I'm using SUMO for (indeed) simulating traffic in a large-scale environment. I would like to simulate different traffic densities and I noticed that the "--scale" option allows scaling the amount of traffic. However, this value and how it affects the simulation is still obscure. What is the bound of this value? How precisely traffic is scaled? Is there a precise explanation of how this works?

thanks :)

Answer 1

The --scale option really scales the whole demand by the factor. So if the factor is 2 whenever a vehicle is going to be inserted by the input definitions two vehicles will be inserted instead. For values < 1 it gets interpreted a s a probability so --scale 0.5 means a 50% chance that the vehicle will be skipped. In theory there is no limit to the value you give here but if the street is full no further vehicles will be inserted immediately and they pile up in the insertion buffer instead. This means they get inserted later when there is sufficient space.