Abstract
This paper presented the VRPTW-D (Vehicle Routing and scheduling Problems with Time Windows-Dynamic) model with real time information on travel times. After applying the model to a test road network, results indicated that the VRPTW-D model presented more efficient routing and scheduling in reducing the delivery costs than those of the VRPTW-F (Vehicle Routing and scheduling Problems with Time Windows-Forecasted) model. This reduction of delivery costs was mainly attributed to the reduction of delay penalty. If the depot costs of construction and maintenance were taken into account, the case with two depots was chosen as the optimal solution with traffic impediments even in urban areas where the land price was very high. It can be noted that efficient vehicle routing and scheduling using the VRPTW-D model can also provide environmentally friendly systems in terms of reducing CO2, NOx and SPM emissions
