中文摘要：

采用江西省宜春市2路公交车早上6：00-9：00的车辆自动定位数据，分析了公交运营中常见的车头时距不稳定现象．对比讨论了6：00-7：00和7：00-9：00两个时段的车头时距稳定性，结果表明：交通状况和客流需求均会影响车头时距的稳定性．为了分析发车间隔对车头时距稳定性的影响，建立了车辆到站时间模型，该模型假设车辆的停靠站延误与车头时距线性相关．采用Matlab对该到站时间模型进行了仿真，仿真结果表明：发车间隔的大小和波动均对车头时距稳定性有影响，发车间隔越大，波动性越小，车头时距越稳定；发车间隔的波动对车头时距稳定性的影响比发车间隔的大小对其的影响更为显著．控制发车间隔的波动可以有效改善车头时距的稳定性，提高公交服务水平．

英文摘要：

The common phenomenon of uneven headway in bus service is explored based on the automatic vehicle location （AVL） data of Route 2 in Yichun City of Jiangxi province from 6：00 to 9：00 in the morning. The headway regularity of two stages 6： 00--7：00 and 7： 00--9：00 is comparatively analyzed, and it is found that both the traffic conditions and the passenger demand affect headway regularity. A bus arrival model, which assumes that the dwell time of a bus is linear in headway, is built to probe the effect of scheduled headway, and the model is simulated by Matlab. The simulation results reveal that the departure intervals and fluctuations affect headway regularity. Longer intervals and less fluctuation mean higher regularity of headway. And, the fluctuation has a more obvious influence on headway regularity than the interval. Controlling the fluctuations of scheduled headway can effectively raise the regularity of headway and improve the level of public transport service.