城市公交车辆碳排放量测算与线网分配方法OA

A top-down approach for measuring vehicle carbon emissions and allocating them to the road network was proposed.Utilizing the statistical energy consumption data of vehicles from public transit enterprises and carbon emission factors,calculation methods for battery electric vehicles(BEVs),plug-in hybrid electric vehicles(PHEVs),and traditional fuel vehicles were studied.Relying on the longitude,latitude,and vehicle speed parameters from high-frequency GPS data,15 km/h was set as the threshold for determining the driving state.Based on the driving coefficient and the auxiliary equipment time penalty coefficient,the relative carbon emission penalty weight for each trajectory point was determined.Furthermore,the spatial congestion penalty coefficient was utilized to correct road segment attributes,and an improved network kernel density function was applied to assign values to the road segments of the transit network.By calculating the normalized weight of each road segment,the total carbon emissions of vehicles were allocated to the transit network according to the weights,thereby determining the carbon emission intensity of each road segment.The results indicate that the proposed measurement and network allocation method for public transit vehicle carbon emissions is feasible,as verified by a case study.The total carbon emissions of public transit vehicles in the example city in 2024 are 204 300 tons.The carbon emissions per 100 km of medium-sized BEVs and large BEVs account for only 59.10%and 65.35%of those of compressed natural gas(CNG)vehicles of the same length,respectively.When the vehicle speed is lower than 15 km/h,the relative carbon emission penalty weight exhibits a non-linear heavy-tailed distribution characteristic.High carbon emission areas are significantly concentrated in congested road segments characterized by heavy traffic volume,dense transit stops,high network density,and frequent traffic lights.The research results will support the optimization of green and low-carbon public transit networks and the targeted governance of local high-carbon-emission road segments.