| Abbreviation | Definition |
|---|---|
| MWS | Man at Work Sign |
| MWT | Manufacturing Warehouse and Transportation |
| MWU | Mid Week Update |
| MY | Model Year |
| N | Narrow |
| N | Near |
| N- | National highway designation |
| NA | North American |
| NAA | National Airspace Analysis |
| NAA | Not Army Aviation |
| NAAQS | National Ambient Air Quality Standards |
| NABI | North American Bus Industries |
| NACA | National Advisory Committee on Aeronautics |
| NACTO | National Association of City Transportation Officials |
| NAD | Naturally Aspirated Diesel |
| NADA | National Automotive Dealers Association |
| NADIN | National Airspace Data Interchange Network |
| NADS | National Advanced Driver Simulator |
| NAERG | North American Emergency Response Guidebook |
| NAGHSR | National Association of Governor's Highway Safety Representatives |