[15.13] Road vehicle interaction with belt skipping

[amis]

Any road vehicle (car, tank) driving on a belt seems to periodically ignore the force created by the belt resulting in two anomalies:
1) vehicle seems to be jumping back and forth on belt even thou rate of speed change is linear
2) vehicle can stop on belt without the belt moving it

Reproduction of 1) (easy):
- place belts on floor in one direction (preferably express for fast results)
- drive on belt in opposite direction
- release throttle
- vehicle will begin jumping back and forth while speed is decreasing
Example video (throttle released at 0:06):


Reproduction of 2) (hard):
- place belts on floor in one direction (preferably express for fast results)
- drive on belt in opposite direction
- decelerate to 0km/h
- if 0km/h is reached when vehicle is "jumping" (ignoring belt force) then vehicle will stop on spot without the belt moving it
Example video (first full stop at 0:09 without bug, second full stop at 0:12 with bug):

[Harkonnen]

Thanks for report. I confirm that this problem exists in 0.15.x. But it is gone in optimized transport belts branch that we will put in 0.16