In order to study the emission patterns of multiple vehicle models under different toll lanes at highway toll stations and the emission reduction potential after ETC promotion. The operating status of vehicles in the MTC (Manual Toll Collection) lane and ETC lane is analyzed. In the MTC lane, vehicles need to go through deceleration, idle, and acceleration stages, but during the idle stage, they will experience queuing and waiting; and when the vehicle is in the ETC lane, it only needs to slow down to a constant speed, pass smoothly, and accelerate away. A comparative analysis was conducted on the carbon emissions of various vehicle types (small buses, large buses, hybrid vehicles, and large trucks) when passing through toll stations. The results showed that for the same vehicle passing through toll stations, the emissions of motor vehicles passing through ETC lanes were significantly reduced, with a 50.45% reduction in carbon emissions for small buses. Promoting ETC lanes on highways is an important measure to achieve carbon reduction.