Kloeden et al (1997) found that "in a 60 kilometres per hour speed limit area, the risk of involvement in a casualty crash doubled with each 5 kilometres per hour increase in free travelling speed above 60 kilometres per hour." The findings were at odds with previous research and understanding of speeding and the road environment. Hence Lambert (2000) reviewed the Kloeden data, and concluded that the data supports that risk of crashes is best represented by a U shaped curve around mean speeds, with crash risk rising for very low speeds, and for high speeds. Further analysis shows that Kloeden et al (1997) report must now be considered to be seriously flawed that the analysis: 1. Does not support that there are any magical properties of the number 60 as in 60 kilometres per hour; 2. Fails to highlight that outcomes only apply to free travelling speed crashes; 3. Fails to recognise that a high BAC applies to the whole trip whereas free travel speed applies to only part; 4. Fails to adjust for the impact of black spots and black links on the findings. (Author/publisher) For the covering entry of this conference, please see ITRD abstract no. E209619. This paper may also be accessed by Internet users at: http://www.rsconference.com/index.html
Samenvatting