In order to accurately reflect the actual traffic operation of the whole region or road network, this study firstly verifies the negative impacts of the spatial imbalance of traffic demand on regional traffic operation through example analysis, and then proposes the principle of 'delay equivalence' as a new criterion for evaluating the accuracy of the regional traffic index. Secondly, the entropy weight method is used to construct the regional traffic index model, which contains factors reflecting the geometric characteristics of road sections, traffic flow characteristics of road sections, topological characteristics of the network, and the characteristics of the network traffic demand imbalance. Taking Yangpu District of Shanghai as an example, it is proved that the traffic index model can accurately reflect the traffic operation situation of the region and has good applicability. This offers significant reference value for relevant authorities in their infrastructure planning and policy-making efforts. Key words:traffic index； spatial imbalance of traffic demand； entropy weighted method； delay per kilometer per vehicle of road network； delay equivalence