I am working on the implementation of the following scenario using OMNET++ (4.6), SUMO-0.22.0 and VEINS-4a2 simulators: exchange of messages between cars which are in the same control area where messages represent the quality of the road.
So, I would eliminate the scenario of accidents between cars in the veins example.
Do I need to change the code of handleSelfMsg () in TraCIMobility and onData () in TraCIDemo11p methods?
The accident-scenario included in Veins is only a very basic one as it only has a single flow of traffic.
As a first step you should create your own SUMO scenario. Tutorials how to do that can be found on the SUMO wiki.
Your second step will be to understand how OMNeT++ works and how to write new applictions for your scenario. Here I recommend doing the Tictoc tutorial and looking at the OMNeT++ user manual.
Further information about Veins can be found on the Veins documentation website.