Validation of capacity reductions in traffic monitoring systems

Both planned and unplanned events can reduce the capacities on roadways and result in congestion and delay. Currently, there are no complete and reliable sources which can be used by traffic operators to estimate capacity reductions. On many occasions, operators have to estimate capacity reductions using a large degree of subjectivity. This paper describes a methodology developed to validate capacity reductions from data collected within the traffic monitoring system. Methods for the determination of normal capacity, short-term and long-term capacity reductions are introduced. The proposed method has been successfully applied to derive capacity reductions using operational data. The results obtained are encouraging. It is believed that the method could be implemented in many traffic control centres to improve capacity reduction estimations