تطابق سرعت هوشمند: صرفه جویی های حوادث و تجزیه و تحلیل هزینه - فایده

The UK External Vehicle Speed Control (EVSC) project has made a prediction of the accident savings with intelligent speed adaptation (ISA), and estimated the costs and benefits of national implementation. The best prediction of accident reduction was that the fitting on all vehicles of a simple mandatory system, with which it would be impossible for vehicles to exceed the speed limit, would save 20% of injury accidents and 37% of fatal accidents. A more complex version of the mandatory system, including a capability to respond to current network and weather conditions, would result in a reduction of 36% in injury accidents and 59% in fatal accidents. The implementation path recommended by the project would lead to compulsory usage in 2019. The cost–benefit analysis carried out showed that the benefit–cost ratios for this implementation strategy were in a range from 7.9 to 15.4, i.e. the payback for the system could be up to 15 times the cost of implementing and running it.

Intelligent speed adaptation (ISA) is the generic name for advanced systems in which the vehicle “knows” the speed limit and is capable of using that information to give feedback to the driver or limit maximum speed. There has been a continual stream of research on ISA in various European countries since a trial with one vehicle conducted in Lund, Sweden in 1991–1992 (Persson et al., 1993). Research projects and trials with ISA are proceeding or have recently concluded in a number of European countries, including Denmark (Lahrman et al., 2001), The Netherlands (Duynstee et al., 2001), Sweden (Swedish National Road Administration, 2001) and the UK (Carsten and Tate, 2000). Sweden currently has several thousand ISA vehicles on the road, most of them with a purely advisory system. The External Vehicle Speed Control (EVSC) project, funded by the UK Department of the Environment, Transport and the Regions, began in February 1997 and ended in February 2000. Its aim was to review a broad range of factors related to the possible introduction of an automatic system to limit the top speed of road vehicles. Phase I of the project was designed as an introductory stage to prepare for the subsequent detailed design and experimental work. Phase II was the main research phase of the project. Its major work was concerned with the delivery of a prototype vehicle, user trials in a driving simulator and on real roads, simulation modelling to predict network impacts of ISA and a review of how ISA could be put into mass production. The last phase of the project reviewed the implications of the earlier work for implementation and prepared a proposed strategy for implementing ISA. In preparing the strategy, the predictions of the safety benefits of ISA that had been made in Phase I were revised, as was the cost–benefit analysis. The aim of this paper is to summarise the work on the safety impacts and costs and benefits of ISA and to review the proposed implementation strategy.

ISA has very large potential to eliminate accidents and reduce the severity of those that do occur. Indeed, it can be considered to be the most powerful collision avoidance system currently available, with the promise of saving accidents on all classes of road and in many if not most collision situations. It is clear from the benefits and cost analysis that the economic of the system are considerable, that the benefits considerably outweigh the costs, and that the benefits of any version of ISA will be maximised with 100% fitment. In terms of how “strong” is the operation of an ISA, the mandatory variants provide the greatest savings in accidents and the highest benefit-to-cost ratios. Accident savings and the cost-effectiveness of ISA would be substantially enhanced by incorporating a dynamic element in the system. There are a number of practical steps that need to taken if ISA is to be implemented, and the sooner that work starts on the standards front, the sooner that the benefits can be realised. Of course, as has been the case with many other safety measures, there may be initial public antagonism to ISA, but is to be hoped that the safety benefits to be realised will be persuasive.