Vehicle speed

The wiki lists vehicle speeds in terms of distance units and days.

Road vehicles

A character with an empty inventory travels at a speed of 10 units per day on any road type.

Vehicle speeds are only affected by road type and load weight.

Tiredness and damage have no effect on traveling speed.

For vehicles that travel on roads, 20 units per day is slow, whereas 100 is very, very fast.

Effect of road type

Certain vehicles can only travel on improved roads - for example, the limousine can only travel on a sand road or better. Improved roads also have higher speed caps - while no current vehicle can travel fast enough to be limited by the speed cap, each road type has a limit on the speed at which a vehicle can travel on it.

Most importantly, each level of improvement makes all vehicles (walking is unaffected) travel 20 to 30 percent faster.

A summary of the levels of road improvement can be found here

Water vehicles

Boats on the water are calculated much differently than those on land. A boat moving 1000 Units does not mean the boat is going 1000 times that of a Cantrian on their legs. There is no basic principle, such as a Cantrian walking down a path, to define how fast or slow a boat is in comparison.

For vehicles that travel on water, 1000 units is slow, whereas 8000 is very, very fast.