| TCRP C-01 | Personal Mobility Aid Securement and Passenger Restraint on Transit Vehicles | Completed | |
| TCRP C-02 | Applicability of Low-Floor Light Rail Vehicles in North America | Completed | |
| TCRP C-03 | Wheel/Rail Noise Mitigation | Completed | |
| TCRP C-03A | Field Testing of Wheel/Rail Noise Control Technologies | Completed | |
| TCRP C-04 | Enhancement of Vehicle Window Glazing for Vandal Resistance and Durability | Completed | |
| TCRP C-05 | Impact of Radio Frequency Refarming on Transit Communications | Completed | |
| TCRP C-06 | Improved Methods for Increasing Wheel/Rail Adhesion in the Presence of Natural Contaminants | Completed | |
| TCRP C-06A | Demonstration of Improved Methods for Increasing Wheel/Rail Adhesion in the Presence of Natural Contaminants | Completed | |
| TCRP C-07 | Technology Assessment of Refueling-Connection Devices for CNG, LNG, and Propane | Completed | |
| TCRP C-08 | A Framework for Evaluating Fuel Options for Transit Buses | Completed | |
| TCRP C-09 | Paratransit Vehicle Specifications and Related Special Maintenance Requirements | Completed | |
| TCRP C-10A | Understanding and Applying Advanced On-Board Bus Electronics | Completed | |
| TCRP C-10B | Hybrid Electric Transit Buses: Status, Benefits, and Issues | Completed | |
| TCRP C-10C | New Designs and Operating Experiences with Low-Floor Buses | Completed | |
| TCRP C-11 | Hazard Assessment and Mitigation of Alternative-Fuel-Related Systems in Transit Bus Operations | Completed | |
| TCRP C-12 | Configuration Options Supplement to Standard Purchase Specifications for Transit Buses | Completed | |
| TCRP C-13 | 30-Foot Transit Bus Technical Specification | Completed | |
| TCRP C-14 | Technical Assistance for Development of Bus Standards | Completed | |
| TCRP C-15 | Assessment of Hybrid-Electric Transit Bus Technology | Completed | |
| TCRP C-16 | Center Truck Performance on Low-Floor Light Rail Vehicles | Completed | |
| TCRP C-17 | Development of Crash Energy Management Performance Requirements for Light-Rail Vehicles | Completed | |
| TCRP C-18 | Strategic Plan for Meeting Transit Industry Wireless Communications Needs | Completed | |
| TCRP C-19 | Guidebook for Evaluating Fuel Choices for Post-2010 Transit Bus Procurements: Update of TCRP Report 38 | Completed | |
| TCRP C-20 | Use of Mobility Devices on Paratransit Vehicles and Buses | Final | |
| TCRP C-22 | Bus Operator Workstation Design for Improving Occupational Health and Safety | Final | |
| TCRP C-23 | Assessing and Mitigating Electrical Fires on Transit Vehicles | Completed | |
| TCRP C-24 | Transit Traction Power Cables: Replacement Guidelines | Completed | |
| TCRP C-25 | Bus Operator Barrier Design | Active | |