Driving and Parking Rules for Hazardous Materials, Including Tunnels and Railroad Crossings
What this domain tests
This domain tests driving and parking decisions for hazardous materials, including tunnel restrictions and railroad crossings. The exam wants you to know when a placarded load may park, when attendance is required, and when a stop at tracks or a tunnel restriction applies.
Core rules
- Parking rules depend on the hazard class and quantity. For certain explosive and flammable loads, federal rules restrict parking within 5 feet of the roadway unless the vehicle is attended, and keep the vehicle away from tunnels, bridges, and populated areas where practical.
- Do not leave a placarded load unattended unless the rules allow it. Set the parking brake, chock wheels when needed, and use warning devices.
- Under 49 CFR 397.11, vehicles carrying certain explosives or flammable gas or liquid may not enter a tunnel unless authorized. Follow posted tunnel bans and state routing signs.
- At a railroad crossing requiring a stop, stop within 50 feet but not less than 15 feet from the nearest rail. Look and listen, open the window, and do not shift gears while crossing. Some crossings are exempt, but do not assume exemption.
Worked example
A tanker with placarded gasoline approaches a tunnel with a flammable-liquid ban and then a railroad crossing. The driver should not enter the tunnel; use the authorized alternate route. At the crossing, stop 15-50 feet from the rail, check both directions, proceed without shifting, and clear the crossing completely.
Traps
Do not treat all hazmat the same for parking; class and quantity matter. Do not stop on the tracks or too close to them. Do not ignore a tunnel sign because the route is shorter. Do not assume a railroad crossing is exempt just because other traffic does not stop.