Heavy vehicle management: signal coordination

Road freight is considered as an important aspect of the growing Australian economy. Between the years 2009 and 2014, there has been an increase of approximately 15% in the number of registered heavy vehicles which include Light Rigid, Heavy Rigid and Articulated Vehicles. The increase in number of heavy vehicles suggests an increase of heavy vehicle traffic in Australia. Due to the operational (acceleration/deceleration, manoeuvrability) and physical (length, size) characteristics of heavy vehicles, they impose negative impacts on surrounding traffic which include increased traffic congestion, traffic safety and environmental impacts such as increased vehicular emissions. Signal optimisation is examined to assess its validity as a tool in managing heavy vehicle movements. Signal coordination which is a form of optimisation can be simply explained as providing cascading green lights on a road to move a platoon of vehicles, without the need to stop at red lights. Signal coordination is known for reducing the number of vehicle stops, delay times, fuel consumption and vehicular emissions. However, those results focused on light vehicles. This research would mainly focus on signal coordination for heavy vehicles in an urban corridor and evaluating the influence of heavy vehicle signal coordination of traffic congestion. The road section that is used in this research is a section of Princes Highway in Melbourne, Australia. This section is 8.8 km long and 13 signalised intersections exist within that distance. This section is selected since it is one of the main corridors in Melbourne with high percentage of heavy vehicles. In addition, many traffic signals exist in the selected section of highway. Based on the results that were yielded in this study, it can be said that signal coordination can be considered as an effective freight management method; which provides reduced congestion rates at road sections with interrupted traffic flows.