8.0 Appendix

8.1 Research methodology

The RAC Report on Motoring 2016 is based on a large-scale internet survey carried out by Quadrangle on behalf of the RAC.

In total, Quadrangle interviewed 1,714 British motorists (i.e. those who hold a current driving licence and drive at least once a month). The survey was conducted in May 2016, with the questionnaire taking around 25 minutes to complete.

The sample was nationally representative of age, gender, socio-economic group, all UK countries and regions, company car drivers and new car buyers.

8.2 Statistical reliability

Any figure taken from a sample can never be taken as a precise indication of the actual figures for the total population being sampled. The figures shown are an estitmate, within a small margin of error, of the actual figures. The error margin varies with the sample size - the larger the sample is, the lower the error will be. It also varies with the proportions answering so the error is lower for a 90/10 result than for a 50/50 result.

In order to illustrate the use of varying sample sizes and their effect on the statistical significance of results, the table below outlines the degree of statistical error broadly associated with different sample sizes from the car drivers' survey. For example, from a sample of 1,000, if 50% answered in a particular way, we would be 95% confident that the true range is between 47% and 53%.

Sample Size % age error:
90/10 result
% age error:
50/50 result
2,000 +/- 2 +/- 3
1,000 +/- 2 +/- 3
800 +/- 2 +/- 3
600 +/- 2 +/- 4
400 +/- 3 +/- 5
200 +/- 4 +/- 7
100 +/- 5 +/- 10