decars1-7, Exercise 3: Cars, deaths and safety measures

Model answer (check the method and figures):

The link: as car ownership and traffic grew in the 1950s and 1960s, road deaths rose in West Germany, reaching a peak of around 19,000 a year in 1970. This created public and political pressure for measures, including a 100 km/h limit on rural roads (1972) and compulsory front seat belts (1976).

How to test whether they worked:
1. Compare deaths before and after each measure, using official statistics.
2. Adjust for traffic: deaths per distance driven, not only totals, since traffic kept rising.
3. Compare with other countries that did and did not adopt similar rules.
4. Look at other changes in the same years, such as better cars, roads, medical care and drink-driving law, which also reduce deaths.
5. Look at studies by road-safety researchers.

Likely conclusion: deaths fell strongly after the 1970s while traffic rose, which suggests the combination of measures worked, though separating the effect of each is hard.