| Transit agency | City | Vehicles operated directly | Website |
|---|---|---|---|
| Des Moines Area Regional Transit Authority | Des Moines | 138 | Official site |
| 10-15 Regional Transit Agency | Ottumwa | 93 | Official site |
| Southwest Iowa Planning Council | Atlantic | 70 | Official site |
| Ames Transit Agency | Ames | 62 | Official site |
| North Iowa Area Council of Governments | Mason City | 50 | Official site |
| Region 12 Council of Governments | Carroll | 49 | Official site |
| Heart of Iowa Regional Transit Agency | Urbandale | 28 | Official site |
| University of Iowa | Iowa City | 28 | Official site |
| Metropolitan Transit Authority of Black Hawk County | Waterloo | 27 | Official site |
| Southeast Iowa Regional Planning Commission | West Burlington | 25 | Official site |
| Southern Iowa Trolley | Creston | 25 | Official site |
| County of Johnson, Iowa | Iowa City | 22 | Official site |
| City of Iowa City | Iowa City | 21 | Official site |
| City of Cedar Rapids | Cedar Rapids | 20 | Official site |
| Linn County | Cedar Rapids | 20 | Official site |
| Siouxland Interstate Metropolitan Planning Council | Sioux City | 20 | Official site |
| City of Dubuque | Dubuque | 19 | Official site |
| Iowa Northland Regional Council of Governments | Waterloo | 19 | Official site |
| City of Sioux City | Sioux City | 18 | Official site |
| City of Davenport | Davenport | 15 | Official site |
| Delaware, Dubuque & Jackson County Regional Transit Authority | Dubuque | 15 | Official site |
| City of Clinton | Clinton | 14 | Official site |
| Mid Iowa Development Association Council of Governments | Fort Dodge | 14 | Official site |
| Washington County | Washington | 14 | Official site |
| Region Six Planning Commission | Marshalltown | 13 | Official site |
| City of Mason City | Mason City | 12 | Official site |
| City of Muscatine | Muscatine | 12 | Official site |
| Benton County | Vinton | 11 | Official site |
| City of Burlington | Burlington | 11 | Official site |
| Iowa County | Marengo | 9 | Official site |
| Jones County | Anamosa | 9 | Official site |
| City of Coralville | Coralville | 7 | Official site |
| City of Marshalltown | Marshalltown | 4 | Official site |
| City of Bettendorf | Bettendorf | 3 | Official site |
| City of Fort Dodge | Fort Dodge | 0 | Official site |
| East Central Iowa Council of Governments | Cedar Rapids | 0 | Official site |
Largest first by vehicles operated directly, as each employer reports it to its federal registry.
Source: Federal Transit Administration, National Transit Database 2024 — Reporter Agency Information. Data captured September 30, 2026.