| Abbreviation | Definition |
|---|---|
| SECUTC | Southeastern Consortium of University Transportation Centers |
| SED | Shipper's Export Document |
| SEER | Seasonal Energy Efficient Rating |
| SEFI | Sequential Electronic Fuel Injection |
| SEJ | Stationary Engine Jerk |
| SEL | Single Engine, Land |
| SEL | Sport Einspritz Long |
| SELNEC | South East Lancashire North East Cheshire |
| SEMI | Tractor-trailer combination |
| SEMTA | SouthEastern Michigan Transportation Authority |
| SEN | Simulated Electronic Navigation |
| SEP | Surface Extension Project |
| SEPTA | South Eastern Pennsylvania Transportation Authority |
| SEQ | Sequential |
| SERT | Special Equipment Release Truck |
| SERVICE | Space Entry Recovery Vehicle in Commercial Environment |
| SERVICE | Space Entry Recovery Vehicle in Commercial Environments |
| SES | Service Engine Soon |
| SET | Safe Effective Transport |
| SEV | Service Exchange Vehicle |