Study population and design

Forty one primary schools in the inner London boroughs of Camden and Islington were invited to participate. These included local authority, voluntary aided (Church of England and Roman Catholic), and private schools. Each head teacher was sent an invitation explaining the trial. Intervention schools would receive assistance and advice from a school travel coordinator, and control schools would receive £150 in compensation for their time. All participating schools were offered an individual report on their school travel patterns on study completion.

A cluster randomised controlled trial was conducted. The school was the unit of randomisation. Consenting schools were randomised to intervention or control group. Prior to randomisation, information was collected on whether the school was local authority, whether road safety improvements were planned during the follow up period, whether the school was already participating in “safe routes to school” or other safety related programmes, and whether the school already had a travel plan. A reasonable balance with respect to these potential confounding factors was achieved by the use of minimisation. An independent statistician carried out the randomisation using the MINIM software programme. The Institute of Child Health Research Ethics Committee approved the study.

Intervention

Intervention schools were offered 16 hours of expert assistance over one school year from one of two part time school travel coordinators who had formal teaching qualifications and road safety experience. Road safety problems and their solutions were identified by meeting with teachers and governors, organising focus groups of parents and pupils, and encouraging the establishment of a school travel working group. Within the working group, specific safety concerns were discussed and advice was given on the development and implementation of a travel plan. The coordinator reviewed draft travel plans and provided advice about how to obtain necessary funding. The coordinator encouraged implementation of the plans by liaison with relevant parties within the local and health authorities.

Outcomes assessment and analysis

The primary outcome measures were the proportion of children who walked, cycled, or used public transport for travel to school on the day of the survey, and the proportion of parents or carers who were very or quite worried about the safety of their children on the daily journey to school in relation to traffic, abduction, and bullying. Primary outcome measures were assessed by a survey administered to the parents of all children in years 2 and 5 in intervention and control schools two months after the intervention was complete. The methods used to implement the survey have been described previously.⁵ The survey was offered in English, Bengali, Somali, Greek, Turkish, Chinese, and Albanian. An identical survey carried out in 1997 provided baseline data for each school on the proportions of children walking to school and of parents very or quite worried about each specific safety concerns.⁵

The secondary outcome measure was the proportion of schools that developed and implemented school travel plans. On completion of the study, the head teachers of intervention and control schools were interviewed to assess whether the school had developed a school travel plan and if any “safe routes” activities had been undertaken. Copies of written travel plans were obtained and examined for the relevant areas covered and the specific components included. The number and quality of actions taken by the local authority were also recorded.

All participating schools were included in the analyses, regardless of the extent of intervention received. We analysed the primary outcome measures using logistic binomial analysis models for distinguishable data (Egret v1.02.10, Cytel Software Corporation, 1997), matching on school and controlling for each school’s baseline proportions of children who walked to school or of parents who were quite or very worried about specific dangers. We examined whether any potential differences in the minimisation factors influenced the results. We assessed the effect of possible confounding factors including year in school, sex, ethnicity, distance to school, survey respondent (mother, father, other carer), home ownership (as a proxy for socioeconomic status), car ownership, maternal paid employment, and whether the child was enrolled in an after school play scheme. Odds ratios and 95% confidence intervals are presented.

Primary outcomes

Table 2⇓ shows the proportions of children walking, cycling, or using public transport on the journey to school in the intervention and control groups. In the intervention schools, 70% of children walked to school, 24% travelled by car, and 6% cycled or used public transport. In the control schools, 71% walked to school, 23% travelled by car, and 7% cycled or used public transport. Table 3⇓ shows the results with and without adjustment for baseline data and for potential covariates. For the journey to school, the adjusted odds of walking, cycling, or using public transport in intervention schools were almost identical to that in control schools (OR 0.98; 95% CI 0.61 to 1.59). Results for travel from school to home in the afternoon were similar (data not shown).

Secondary outcomes

Two of 11 intervention schools and one of 10 control schools reported having travel plans prior to the study. One year later, nine of 11 intervention schools and none of 10 control schools had a written travel plan. None of the 11 intervention schools took action in all four recommended areas in government “Best Practice” guidelines for school travel plans. However, of the nine intervention schools developing their travel plan within the project time frame, all implemented some form of Safe Routes activities (table 4⇓), compared to four of the 10 control schools.