Driving time formula
Divide distance by average speed to estimate time in motion. Add fuel, food, charging and rest stops plus a separate traffic allowance.
Total time = distance ÷ average speed + stops + traffic delay
Use average speed, not the speed limit
Average speed includes slower roads, intersections and congestion while the vehicle is moving. A highway posted at 70 mph rarely produces a 70 mph average across the entire trip.
Plan stops separately
Long trips need safe rest breaks. EV charging, border crossings, ferries and weather can add more time than ordinary fuel stops, so enter a realistic combined allowance.