Heavy vehicle management: signal coordination vs. restriction strategies
Creators: name: AL EISAEI, MOHAMMED HAMAD ZAYED SULAIMAN
Publisher: name: RMIT University
Year: 2024
Subjects: classificationCode: 400512
subject: Transport engineering

description: Road freight is an important aspect of the growing Australian economy. Between 2009 and 2014, there has been an increase of approximately 14.7% in the number of registered heavy vehicles, including light rigid, heavy rigid and articulated vehicles. Due to the operational (e.g. acceleration/deceleration, manoeuvrability) and physical (e.g. length, size) characteristics of heavy vehicles, they impose negative impacts on surrounding traffic, including increased traffic congestion, reduced traffic safety and environmental impacts, such as increased vehicular emissions (hydrocarbons, carbon monoxide, NOx and carbon dioxide). The negative impacts imposed by heavy vehicles are intensified at interrupted traffic flows due to the presence of traffic lights. The acceleration/deceleration performance of heavy vehicles at traffic lights is lower than that of light vehicles.<br><br>Due to the physical and operational characteristics of heavy vehicles, they impose negative impacts on the surrounding traffic. Different strategies have been applied to urban corridors to mitigate these impacts. Signal coordination will be implemented as a heavy vehicle management method. This research will test whether signal coordination may be a viable option to control heavy vehicles on an urban corridor. On the other hand, this research will implement a restriction strategy which restricts heavy vehicles based on their type (rigid, heavy combination and multi combination) as another form of heavy vehicle management. The road section that is used in this research is a section of Princes Highway in Melbourne, Australia. This section is 8.2 km long with 3 lanes on each direction, and 13 signalised intersections within that distance. This section is selected since it is one of the main corridor in Melbourne with high percentage of heavy vehicles. In addition, many traffic signals exist in the selected section of highway which forms interrupted traffic flows. The research is initiated by modelling the corridor of study using VISSIM microscopic traffic simulation package. The model is built based on the physical characteristics of Princes Highway including number of lanes, lane widths, entry points and exit points.<br><br>In this research, signal coordination is examined to assess its validity as an efficient method to reduce congestion caused by heavy vehicles. Three different signal coordination set-ups are used in this research. The first set-up targets passenger cars as the main beneficiary of signal coordination. The second set-up targets heavy vehicles as the main beneficiary of signal coordination. The third and final set-up targets all vehicles on the corridor. The influence of signal coordination was evaluated at existing heavy vehicle compositions, then the heavy vehicle composition is increased at 5% increments reaching up to a 30% heavy vehicle composition. Increasing the heavy vehicle compositions tested the ability of signal coordination to cope with the increased number of heavy vehicles in the corridor. The results from this research shows that signal coordination can be used as a heavy vehicle management method on a highway with interrupted traffic flows and during congestion. In addition, this research also shows that signal coordination is capable of handling high heavy vehicle compositions.<br><br>On the other hand, three restriction strategies are evaluated in this thesis. Each restriction strategy restricts a certain type of heavy vehicle. The heavy vehicle types are categorised based on the guidelines used in the State of Victoria, Australia. The first management strategy restricts multi combination vehicles from using the corridor. The second strategy restricts multi and heavy combination vehicles from using the corridor. The third strategy restricts all heavy vehicles from using the corridor. This research has provided insight on the influence of a vehicle type restriction strategy. The main reason for proposing such a restriction strategy is to differentiate between the types of heavy vehicles and provide a clear picture of the influence that each heavy vehicle type poses on the surrounding traffic.