| Abbreviation | Definition |
|---|---|
| ARFF | Awesome Racing Flyball Fanatics |
| ARH | American Racing Headers |
| ARL | Apex Racing League |
| ARP | Automotive Racing Products |
| ARRC | American Road Race of Champions |
| ARRS | Association of Road Racing Statisticians |
| ARSH | age race sex and Hispanic |
| ARSO | Audi Racing Sport Organisation |
| ART | Advanced Racing Technology |
| ARTA | Autobacs Racing Team Aguri |
| ARWS | Adventure Racing World Series |
| ASCAR | American Stock Car Auto Racing |
| ASR | Active Suspension Racing |
| ASRA | All Star Racing Association |
| ASRA | American Sportbike Racing Association |
| ASRA | Arizona Sports Racing Association |
| ASRS | American Sim Racing Series |
| ASVD | Auto Sport Vereniging Denekamp |
| ASWR | Art Space Waste Race |
| ATC | Achilles Track Club |