Caravan duration during planning does not match actual duration

[jaype87]

During planning of a vehicle caravan, the total route time is shown as much higher than the actual time, once the caravan is moving, the estimated time to destination is much lower.

To Reproduce
Steps to reproduce the behavior:

1. Create a vehicle caravan
2. Load a driver
3. Select a destination and note the route time
4. Start the caravan
5. Once the caravan left the map, check the time to destination

Screenshots
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