This project started with a review of current intelligent transport systems (ITS) performance evaluation practices amongst Austroads agencies. The VicRoads methodology in the ITS performance monitoring report was adopted and generalised, and a five step ITS performance evaluation framework was established to retrieve, analyse and report asset performance from the user perspective. Asset availability estimated from major alarms was used as the key performance indicator. Asset alarm data for SCATS signals, motorway electronic variable speed limit (EVSL) signs, and school zone electronic speed limit signs (ESLS) were collected from various Austroads jurisdictions to demonstrate the processes of the methodology. The initial results of SCATS signal performance for four major alarms, blackout, flashing yellow, watchdog and intersection fallback, in the calendar year of 2013 from seven jurisdictions were reported. The signal availability benchmarks, including the lowest performance threshold and optimal performance levels for average availability and availability against level-of-service, were also identified. The congestion impact on the community during signal failure for the seven jurisdictions was estimated to be $258 m in 2013 if adopting the VicRoads unit costs. When EVSL or ESLS were configured in the STREAMS Business Intelligence (BI) system, the asset availability could be analysed and reported consistently. The motorway EVSL performance and benchmark based on STREAMS BI reports in 2014 from five motorways in VicRoads and TMR were also analysed. The methodology developed and tested in the report is deemed to be feasible as the basis of a national process for Austroads jurisdictions to collect, analyse and report the performance of critical ITS assets consistently across all jurisdictions. Austroads jurisdictions would like to monitor their ITS asset performance from a user perspective. The following actions were recommended for consideration by Austroads: 1. Only critical ITS assets that are contributing to journey planning, congestion management and traffic control should be performance monitored and benchmarked from the user perspective. These critical assets include traffic signals, EVSL and/or lane use management system (LUMS), freeway data stations, ramp metering, variable message signs and communication systems. 2. Austroads should continue to collect, analyse and report the asset performance data for all jurisdictions for another 12 months by using the process and tools developed in the report. The asset performance reporting results presented in the current report and for the next 12 months should be analysed together to understand yearly trends and improve the current methodology. It is expected that ITS asset performance monitoring and benchmarking results would be reported and published regularly in future. 3. Further fine-tuning of the methodology would also be required such as validating the VicRoads unit delay costs during signal failure by using the empirical delay data from the road networks and quantifying possible impacts on the community during the failure of other critical ITS assets (e.g. EVSL, variable message sign (VMS), ramp metering etc.). (Author/publisher)
Abstract