This study proposes a method for structuring stochastic link travel times in a road network with stochastic traffic demands. In our proposed method, the uncertainty of travel time is evaluated by link-flow-based indices. The mean link travel time is represented by using both its mean link flow and the corresponding risk premium of the stochastic link flow. The risk premium is defined by a concept of certainty equivalent derived from the relationship between a stochastic link flow and a link cost function. By expanding the concept of risk premium, a calculation method of link travel time covariance is proposed. Our proposed method defines bi-variate risk premiums, by which the mean of the product of two stochastic link travel times can be calculated. As a numerical calculation, we demonstrate our proposed method in a test network. Finally, we conclude and show future directions for evaluating real road networks.

这项研究提出了一种在具有随机交通需求的路网中构造随机链接旅行时间的方法。在我们提出的方法中，行程时间的不确定性通过基于链接流的指标进行评估。平均链路行程时间通过使用其平均链路流量和相应的随机链路流量风险溢价来表示。风险溢价由确定性当量的概念定义，该确定性从随机链路流量和链路成本函数之间的关系得出。通过扩展风险溢价的概念，提出了一种行进时间协方差的计算方法。我们提出的方法定义了双变量风险溢价，通过该风险溢价可以计算出两个随机链路旅行时间乘积的平均值。作为数值计算，我们在测试网络中演示了我们提出的方法。最后，