Tanker · Safe Driving Rules

You have to make a quick stop in a tank vehicle to avoid a crash. What does CDL manual guidance warn against doing at the same moment?

1.Steering quickly while braking can roll the vehicle, part of the wider warning against over-steering, over-accelerating, and over-brakingCorrect answer

2.Settling the liquid by accelerating hard first, so that the entire load sits at one end of the tank before the brakes are even applied

3.Nothing in particular, since once the brakes are fully applied a tank vehicle is assumed to behave exactly like any ordinary dry van trailer

4.Slowing the trailer first with the trailer hand valve alone, so that the tractor is supposedly not pushed forward from behind by the trailer

Explanation

Guidance warns that steering quickly while braking may roll the vehicle over, and places it alongside the general caution against over-steering, over-accelerating, and over-braking, any of which can put a tank vehicle into a skid. The combination is worse than either input alone because hard braking already loads the front of a top-heavy vehicle and throws the liquid forward, and a sharp steering input then adds a lateral wave to a vehicle whose weight is high and moving. This is manual teaching: 49 CFR 383.119(i) makes operating practices and procedures not otherwise specified a required knowledge area for the endorsement, and states no technique. The wrong options go the other way, adding a violent input before the stop, denying that a liquid load changes anything once the brakes are applied, or reaching for the trailer hand valve, which is not a tool for slowing a trailer ahead of the tractor.

Source: 49 CFR 383.119(i)

Drill Safe Driving Rules questions

You have to make a quick stop in a tank vehicle to avoid a crash. What does CDL manual guidance warn against doing at the same moment?

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