Table 3

Main findings of systematic reviews on environmental interventions to improve health through transport

Modes of interventionQuality IndicesMain results
RR, risk ratio.
Public lighting445,46Night time accidents were reduced by 15–35% as a result of public lighting interventions. The effect size was greater where more accidents occurred at night as compared with during the day. Fatal accidents reduced by 65% (range 52–75%) and property damage reduced by 17% (range 13–21%). The effects were also dependent upon the decade of study (greatest in the 1980s), the country of study (largest effect in Israel, smallest effect in Denmark), rural areas benefited more than urban environments, and pedestrians benefited more than other street users.
Guardrails and crash cushions447Installing median barriers increases the total number of accidents by about 30% (p<0.05).
Severity of accidents is reduced. New median barriers reduce the probability of fatal accidents by 32% (range 14–46%), given the total number of accidents, but apparently have no effect on the probability of injury accidents (−2%, −7–4% change).
Guardrails reduce both the number of accidents (by 27%, range 18–35%) and their severity.
Crash cushions reduce both number (84%, range 74–90%) and severity of accidents although studies are few and of doubtful validity.
Modifiable risk factors for child pedestrian injuries348Child risk factors, in order of effect size, are age, behaviour, race, and sex. Social and cultural risk factors increasing likelihood of child pedestrian injuries are income (RR 5.7), crowding (RR 1.3 to 3.4), mother’s working status and history of hospitalisation (RR 2–2.5), illness in the family (RR 2.3), and mother’s education. Physical environment risk factors are, in descending order, volume of traffic, speed limit, predominant type of dwelling, absence of play area, location on road, protection of play area, proportion of curb side parking, street mean vehicle speed, shared driveway, type of road, time of day, weather, and lighting.