Nine Hours In, Empty Tank, Placards Still Up
It is 9:15 p.m. in Springfield, Missouri. You have just finished unloading 8,500 gallons of gasoline from your DOT-406 cargo tank at a terminal. The tank is empty except for residue. The Class 3 placards are still on all four sides, and the shipping paper bearing the residue notation is in the cab. You have driven 9 hours and live 40 miles north; you plan to sleep 7 hours and roll at 5 a.m. Two options are available: a shopping-center lot 3 miles away with a large, unlit, open parking area and no fencing, or a truck stop 2 miles away with a lighted, fenced rear lot used regularly by tankers. You are alone, with no co-driver.
1. Is the tank still regulated after unloading? Address placards and paperwork.
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Yes. An empty cargo tank that has not been cleaned and purged still contains a residue of a material that requires placarding, so the Class 3 placards stay up and the shipping paper continues to travel with the vehicle, with the residue notation. The hazards that make gasoline placarded do not disappear when the liquid stops flowing; the vapor space in an empty tank is the dangerous part.
That means every rule that attaches to a placarded vehicle still attaches to you tonight: parking restrictions, attendance requirements, no smoking, and routing. Treating the tank as 'empty and harmless' is one of the classic ways a driver ends up parked where a placarded tanker is not allowed to be.
2. Choose a parking location and justify it under the parking and attendance rules.
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Take the truck stop's fenced rear lot.
The parking rule bars parking a placarded vehicle within 5 feet of the traveled portion of a public street or highway, and generally bars parking on a public street or highway except when necessary for the performance of your duties or in an emergency. The attendance rule requires the vehicle to be attended at all times unless it is parked in a secure location, meaning a designated parking area, a consignor's or consignee's premises, or a place where it is protected from unauthorized entry.
The shopping-center lot fails the secure-location test. Private property is not automatically secure; an unlit, unfenced lot invites tampering, and a placarded gasoline tanker sitting alone in it overnight is a foreseeable problem. The fenced, lighted lot used by tankers is the defensible choice. Park away from buildings and fuel islands, set the brakes, lock up, and check in with the lot staff.
3. You sleep in the bunk at the truck stop. Does that count as attended, and what do you check before sleeping?
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Yes. A vehicle is attended when the responsible person is in or near it, with an unobstructed view, and is able to move it. Sleeping in the bunk of your own placarded tanker in a designated, secure lot satisfies both the parking rule and the attendance rule.
Before you climb in the bunk, do a real walkaround rather than a glance: dome covers, valves, piping, and the ground under the tank for anything wet. Confirm the placards are still on all four sides and the shipping paper and ERG are where you can grab them in the dark. Note your exact location and the nearest exit route, and make sure the lot staff can reach you.
The moment you leave the vehicle to shower or eat, it is unattended, and it must already be in a secure location when that happens. If you later decide to drive home, remember the truck is still a placarded hazmat vehicle all the way to your driveway, and a residential street is not a lawful place to leave it.