| Abbreviation | Definition |
|---|---|
| SOCRATES | System of Cellular Radio for Traffic Efficiency and Safety |
| SOG | Speed Over Ground |
| SOHC | Super Outstanding Hyperspeed Car |
| SOHO | South Of HOuston Street |
| SOI | Signal Operation Instructions |
| SOIR | Simultaneous Operations On Intersecting Runways |
| SOIWR | Simultaneous Operations On Intersecting Wet Runways |
| SOLAS | Safety of Life At Sea Convention |
| SolTrans | Solano County Transit |
| SOM | Self Organizing Map |
| SORN | Statutory Off-Road Notification |
| SORSA | Society of Road Safety Auditors |
| SOS | Safe Operating Speed |
| SOV | Single Occupancy Vehicle |
| SOV | Single Occupant Vehicle |
| SOV | Special Operations Vehicle |
| SOV | State Owned Vehicles |
| SOV | Super Octane Vehicle |
| SOX | Sulfur Oxide |
| SOZ | Spirit Of Zopilote |