Reducing greenhouse emissions by improving traffic signal operations.

The reduction of transport related greenhouse gas emissions is a multi-faceted challenge for road management authorities. Many road management authorities operate area traffic signal management systems such as the Sydney Coordinated Adaptive Traffic System (SCATS) or Split Cycle Offset Optimisation Technique (SCOOT). Despite the dynamic nature of area traffic signal management systems and their ability to react to changing traffic demands, sometimes on a cycle by cycle basis, longer term changes in traffic patterns and increasing congestion requires the periodic review of system settings. This paper describes a study undertaken to assess the greenhouse emissions benefits of reviewing and improving the SCATS operation of several routes in Adelaide. The methodology is outlined, including the use of an instrumented vehicle and global positioning system (GPS) travel data. Data was collected before and after the implementation of revised SCATS settings for each route. Reductions in emissions in terms of carbon dioxide equivalents, of between 1.4 per cent and 5 per cent were found. Estimates of changes in other gaseous and particulate emissions are also provided and discussed. (a) For the covering entry of this conference, please see ITRD abstract no. E217099.