Annual Average Daily Traffic

Annual average daily traffic is the total volume for the year divided by 365 days. The traffic count year is from October 1st through September 30th. Very few locations in California are actually counted continuously. Traffic Counting is generally performed by electronic counting instruments moved from location throughout the State in a program of continuous traffic count sampling. The resulting counts are adjusted to an estimate of annual average daily traffic by compensating for seasonal influence, weekly variation and other variables which may be present. Annual ADT is necessary for presenting a statewide picture of traffic flow, evaluating traffic trends, computing accident rates. planning and designing highways and other purposes.Traffic Census Program Page年平均日交通量（Annual Average Daily Traffic，以下简称ADT）为全年交通总流量除以365天所得。 交通统计年度的周期为每年10月1日至次年9月30日。 加利福尼亚州内几乎没有点位会开展连续交通计数。 交通计数工作通常依托电子计数设备完成，此类设备会在全州各点位间轮换部署，以实施持续性交通计数抽样项目。 所得计数结果需通过校正季节影响、周度波动及其他潜在变量，调整为年平均日交通量的估算值。 年平均日交通量数据对于呈现全州交通流量概况、评估交通发展趋势、计算事故率、规划与设计公路等诸多工作均不可或缺。 交通普查项目页面