Measuring the impacts of rail-based park-and-ride facilities on commuting behaviour in Cape Town: findings and methodological lessons

Abstract

Paper presented at the 30th Annual Southern African Transport Conference 11-14 July 2011 "Africa on the Move", CSIR International Convention Centre, Pretoria, South Africa.

This paper reports upon the findings of a study undertaken in Cape Town to measure the impacts of park-and-ride facility upgrades on commuting behaviour at selected rail stations. The study analysed data from two sources covering the period before and after park-and-ride facility upgrades at three affected rail stations (Brackenfell, Kraaifontein and Kuilsrivier) and three contorl stations. The first data source took the form of parking counts and vehicle number plate recordings (n=6,501) over a period of 12 months. The second took the form of an (n=400) intercept survey of park-and-ride users at the affected rail stations. The parking count data revealed dissimilar before-and-after impacts across the affected stations: increases of 13%, 27% and 44% in observed vehicles at Brackenfell, Kraaifontein and Kuilsrivier stations respectively, compared to a mean increase of 14% across the control stations. Combined, the weighted mean increase observed at the affected stations was 29%, suggesting that the park-and-ride improvements wuld have resulted in an increase in users in the order of 15%. Utilisation rates were found to be highly variable, with clear evidence of 'churning' behaviour. The intercept survey data revealed that 16% of the 43 new park-and-ride users interviewed were previously rail users who did not use any park-and-ride facility, and 67% were car users. Given the absence of evidence of a uniform impact on commuting behaviour, a further (n=400) survey of non-users within the catchments of the affected stations was conducted to gauge how effectively the park-and-ride upgrades had been marketed. It was found that 56% of respondents were aware of the upgraded facilities, of whom 66% had heard of the facilities via the City of Cape Town's marketing strategy The paper concludes with a discussion on how the City of Cape Town's park-and-ride strategy might be improved to increase its impact, and with a reflection on methodological lessons, particularly with respect to the value of longitudinal data collection in before-and-after comparisons.