Bug discovered in version 0.10.1.
When the "--check-accidents" option is not entered in sumo, attempting to load a simulation with vehicles to the point where the road system can accept no more vehicles will crash the simulator. Note: gui-sim cannot use the "--check-accidents" option. The crash is caused by a negative variable assignment in MSVehicle::moveRegardingCritical. At times of high congestion in the simulator, a road can be too congested to fit newly generated vehicles. The vehicle will be inserted slightly overlapping another vehicle creating a negative gap between it and its surrounding vehicles. A negative gap value is ignored by Sumo if the MSGlobals::gCheck4Accidents option is not ticked 'if (MSGlobals::gCheck4Accidents && gap<0)'. The negative value will then cause the simulator to crash.