100
100 feet.
These vehicles must stop no close than 15 feet and no more than 50 feet away from the nearest rail.
600 feet
50 Feet
For less than 500lbs it's 2500 feet. Anything over 500lbs is 4000 feet
Smoking is prohibited within 50 feet of explosive-laden vehicles to ensure safety and prevent any accidental ignition of flammable materials.
2500 feet
This question refers to the US standard rules established by the MUTCD (Manual of Uniform Traffic Control Devices) for approach to railroad crossing. Unless a highway-railroad grade crossing is marked with an "EXEMPT" sign, the named vehicles are required to stop not closer than 8 feet from the crossing gate, if equipped, and not closer than 15 feet feet from the closest rail. There is no "farther than" in the Federal requirements or recommendations. The "farther than" is likely a CDL or state requirement.
200 feet
Your feet to jump
A locker for your feet.
300