In this study, the authors show the conceptual design of a comprehensive dynamic departure scheduling and vehicle dispatch system for truck-mixers, which enables just-in-time arrival of truck-mixers. The dynamic departure scheduling system for ready mixed concrete decides optimal departure timing from the concrete plants considering two elements. The first is travel time fluctuation caused by road traffic congestion, and the second is divergence between actual and planned concrete placing process at the construction sites. The information server collects shipping status from the concrete plant, positions and status of truck-mixers, progress reports from concrete placing sites using global positioning systems (GPS), personal digital assistants (PDA) and mobile communication systems. Introduction of this dynamic departure scheduling system will reduce traffic congestion caused by waiting trucks around the sites, and will improve the quality of concrete by the reduction of transportation time. The proposed system is now at development stage and planned to be experimented on some actual construction sites for evaluation by the end of fiscal 2001.
Abstract