omnet++ - what policy is based vehicle rerouting in case of accident?

Question

I'm doing a scenario where there is 1 route at the beginning and then it splits into 3, then merges into 1 again. I'm stopping the car in the first lane, the second car stops also, the third one reroutes in the middle lane, the fourth goes to the queue, the fifth reroutes, the sixth goes to the queue, the seventh reroutes.....why is it behaving like that? I can't understand where to change this "balancing" or "threshold". Any suggestion?

Answer 1

The Veins 4.6 sample application behaves as follows:

• if a vehicle is stopped (and has been driving) and has not yet sent a warning message, it sends a message containing its current road (TraCIDemo11p.cc, line 82)
• if a vehicle receives a warning message, it tries to find a new route through the road network that avoids this road (TraCIDemo11p.cc, line 48); in addition, if it has not yet sent a warning message, it re-sends the received message (TraCIDemo11p.cc, line 54)

So, if you use this sample application and observe that some vehicles do not change their route, this can be attributed (among others) to either of the following effects:

• they never received a message that told them about the congestion
• they received a message, but couldn't find a route through the road network that would avoid the congestion

Why a vehicle did not receive a message can again be attributed (among others) to any of the following:

• a warning message was transmitted to them, but they could not receive it (e.g., due to interference)
• a warning message was transmitted through the network before they started their trip (remember, warning messages are not repeated by the example application)