Trucking Glossary

The steepness of an uphill or downhill road, often expressed as a percentage, not an angle or speed limit.

A descending road in the direction of travel, commonly used in long-grade warnings; the opposite is upgrade.

Reduced braking effectiveness associated with conditions such as overheating. Greater pedal force does not establish restored braking.

A facility providing emergency deceleration or stopping space for an uncontrolled vehicle, particularly after brake failure; also called an escape ramp.

A road control requiring traction equipment under specified conditions. Requirements depend on the vehicle, location and current directions.

A designated area for fitting traction equipment, subject to local use and stopping rules.

A category of tire equipment intended to improve traction, braking or steering on snow or ice, including qualifying chains and alternatives.

A thin transparent ice layer through which the pavement remains visible, often difficult to distinguish from a wet road.

Wind acting across the vehicle, with effects depending on vehicle profile, loading, wind strength and exposure.

How clearly and far the surroundings can be seen in conditions such as fog, rain, snow or smoke; it may change quickly.

A person coordinating drivers’ work: communicating pickup and delivery details, tracking progress, and handling changes. Some also find loads and negotiate rates. Dispatchers may work inside a carrier or provide an outside service.