| Abbreviation | Definition |
|---|---|
| ISL | Island Line |
| ISLG | Infrastructure Safety Liaison Group |
| ISO | International Standards Organization |
| ISP | Long Island Mac Arthur Airport |
| ISPS | International Ship and Port Security |
| ISRV | Intelligence Surveillance and Reconnaissance Vehicles |
| ISRV | Intelligence Surveillance Reconnaissance Vehicle |
| ISSC | International Ship Security Certificate |
| ISU | Internal Airlift / Helicopter Slingable Container Unit |
| ISV | Innovative Space Vehicle |
| ISVS | Identical Special Vehicles See |
| IT | Individual Transportation |
| ITA | Integrated transport authorities |
| ITA | International Taxicab Association |
| ITA | International Trade Association |
| ITAB | Intermodal Transportation Advisory Board |
| ITC | Ignition Timing Control |
| ITC | In The Canal |
| ITC | Intelligent transportation system |
| ITC | International Tonnage Convention |