为了应对未来重型车国七排放标准对实际道路测试冷起动排放的考核，研究了重型车实际道路行驶工况下的冷起动特征，对8个型号的36台在用重型车，共计16 629.4 h的远程监控排放数据进行分析研究。结果表明，对于相同用途的车辆，平均行程时长和平均行程做功随着最大总质量的增长而升高。所有样车的平均冷起动时长为912.4 s，冷起动占行程时长的平均比例为38.58%，平均冷起动做功的世界统一瞬态循环（WHTC）循环功倍数为0.25。对于实际驾驶工况，由于环境温度较低、频繁起停或长怠速的影响，车辆有可能运行较长时间仍无法完成热机。重型车的冷起动排放优化将是应对未来排放标准升级的挑战之一。

In order to meet the requirements of the future assessment of the China Ⅶ emission standard for heavy-duty vehicles on cold start emissions during real road tests, the cold start characteristics of heavy-duty vehicles under real road driving conditions were investigated, and 16 629.4 h remotely monitored emission data from 36 in-use eight-typed heavy-duty vehicles were analyzed and studied. The results show that for vehicles with the same usage vehicles, the average trip duration and average work increase with the increase of the maximum gross mass. The average cold start duration of all vehicles was 912.4 s, the average proportion of cold start duration was 38.58%, and the World Harmonized Transient Cycle (WHTC) cycle power multiplier of the average cold start work was 0.25. For real driving conditions, the vehicles might run for a long time without being able to complete the warm-up due to the effect of low ambient temperature, frequent start-stop, or long idling speeds. Optimizing cold start emissions for heavy-duty vehicles would be one of the challenges in meeting future emission standard upgrades.