| Title Sort descending | Description |
|---|---|
| HCM | Highway Capacity Manual. An engineering reference manual for road design. |
| HCR | High Capacity Road |
| HGV | Heavy Goods Vehicles. Typically refers to trucks over 3.5 tons |
| HMI | Human-Machine Interface. A front-end user interface. |
| HOT | High-Occupancy Toll Lanes (HOT lanes) are Priced Managed Lanes open to High-Occupancy Vehicles (HOVs) at a discounted toll rate or free of charge. Vehicles with one occupant may also use the HOT lanes but with payment of the posted toll rate, which is often variable. |
| HOV Lanes | High Occupancy Vehicle Lanes (HOV Lanes) are unpriced managed lanes with access limited to vehicles with two or more occupants. Tolls are not collected in HOV lanes. |
| Hub | Or “Clearinghouse Hub”, is a node on the Clearinghouse Network, interfaces to all other Hubs on the Clearinghouse Network. |