Priority scheduling of urban rehabilitation streets to minimize congestion, delays, and accidents

This paper describes the framework of a priority scheduling algorithm that minimizes traffic congestion, travel delays, and accidents that occur during the rehabilitation of urban streets. The process utilizes: (i) GIS technology for storing and visualizing the necessary data of streets, and for applying traffic assignment, (ii) previous research on the costs of congestion, travel delays, and accident rates, and (iii) utility theory for combining the values of the qualitative and quantitative attributes associated with road rehabilitation. The priority scheduling framework, developed in the research, has been applied to an example town with a population of 116,000, in which 10 street links were selected for repaving in 3 time phases, each of two months, during one construction season. By comparing the multi-attribute utilities of the three attributes using the proposed priority schedule, against the average multi-attribute utilities of 10 random time-schedules of the 10 streets (standard practice), the proposed construction scheduling algorithm yields a saving of 13 veh-hrs/hr in network travel time, $127/hr in the cost of comfort and convenience, and 11 accidents per year. Further research is required for coding the proposed algorithm into an expert system that practitioners can easily learn to use and draw priority schedules for their road rehabilitation programs.