Abstract
This paper examines the question of assessing the costs and benefits of safety and shows how they cannot logically be separated from the costs and benefits of mobility. Although the value of life and the value of time are difficult to estimate, there are means available for approaching monetary values. The literature on the value to society of life and time is reviewed, with particular reference to the Human Capital (HC) approach and the Willingness-To-Pay (WTP) approach; literature is also reviewed on transport costs resulting from deaths, injuries and property damage in road traffic accidents. The calculations are given in approximate form for one well-known safety intervention: the US 55 mph speed limit. (A)