Excessive and inappropriate speed on our roads is a significant issue in New Zealand, and loss-of-control crashes, on rural curves in particular, are a key crash contributor. This research investigated the deployment of an advisory intelligent speed adaptation (ISA) system in New Zealand.
The predicted crash-reduction benefits of two ISA variants were determined following real-world trials of a 'fixed' ISA system that provided drivers with speed limit information and warned them when they were exceeding the speed limit, and a 'variable' ISA system that provided drivers with feedback on their speeds while negotiating curves and other road features that were signposted with advisory speeds. These crash-reduction benefits were compared with estimated implementation and operating costs to determine the economic viability of deploying an advisory system in New Zealand.
The research also examined a range of potential barriers. Focus groups were used to identify user acceptance issues, and local and central government and the motor industry were consulted to identify potential institutional, regulatory or other barriers.
This research also looked at how speed limit and advisory curve information may be transferred to a vehicle. An assessment of GPS reliability and coverage in New Zealand was made, as well as the development of a framework on which to build an e-speed limit management system.