To include the cost of accidents in the cost-benefit assessment of a transport policy which is likely to result in modal transfer, it is necessary to predict the associated change in the number of accidents by reference to casualty rates disaggregated by mode. The casualty rates per kilometre given here apply to the six former metropolitan counties and are based on accident data from national police records and travel data from the 1987/9 national travel survey. Average rates varied from 1200 casualties per hundred million kilometres for motor cyclists on weekdays (1600 at the weekend) down to about 15 casualties per hundred million kilometres for bus passengers. A similar pattern of risk applied to males or females travelling on weekdays or at the weekend and, again, when the rates were translated into money costs: 1000 per ten thousand kilometres at 1986 prices for motor cyclists on weekdays (1600 at the weekend) down to less than 5 per ten thousand kilometres for bus passengers. The county casualty rates were only half the corresponding values for London for most modes, and lower still for bus passengers. The lower risk for car drivers appeared to be related to lower levels of traffic flow in the counties. Higher levels of severity outweighed the lower levels of risk to give cost rates similar to those for London. The county casualty rates and cost rates were both similar to national estimates. (A)
Abstract