Glossary
 
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
 
H

• Hazard Class: numerical designation of the primary transportation hazard based upon the chemical and physical properties of the hazardous chemical. For example, the hazard class assigned to acetone is 3, which corresponds to a flammable liquid. See list of hazard classes that Yellow transports.
• Hazardous Material (HM): a substance or material which has been determined by the Department of Transportation to be capable of posing an unreasonable risk to health, safety and property when transported in commerce. A complete listing of hazardous material can be found in 49 CFR 172.101.
• Heater Service: the protection of freezable shipments by heat.
• High Cube: a trailer body with above average cubic content.
• Hot Tag: a shipment requiring special handling to achieve earlier-than-normal delivery service.
• Hub: terminal serving regionally located end-of-line terminals as breakbulk. The hub of a "hub and spoke system" is the breakbulk and the spokes lead to the EOL terminals it serves.
• Hundred Weight: a statement of weight meaning 100 pounds, abbreviated CWT.