Replace the notion of ghost traffic with the notion of background traffic
The background traffic is composed of two parts. The first part is the traffic that is not generated by the demand (transit traffic, professional traffic, ...) and the second is the traffic coming from the demand but not generated because of the way to demand is assigned on the network. Indeed, the traffic state network should not depend on the od layer. In the case of a small number of od points, it is possible that some trips have the same origin and destination. In this case, the associated vehicle must be created in order to keep the same accumulation.
TO DO: Add this second part of background traffic
Each time a trip has the same origin and destination, a background vehicle is created
Each time the accumulation per mode is updated by the engine flow, the remaining distance for the background vehicle should be calculated from the reservoir speed