Some cars already have the integration between waze and its onboard system, I believe this functionality can be exploited in the best way.
How to apply the improvements:
Speed: If the speed is higher than the speed of the road, the application along with the car system changes the speed of the CAR in colors such as green (below speed), yellow (speed near the limit), red ( speed above the limit).

Petrol Stations: Check the percentage of gasoline in the car and inform the nearest gas station (thus the propagation would be more effective, since it would be a user need to refuel).