Shifting from car to active transport: A systematic review of the effectiveness of interventions

Highlights

• Active transport has potential health benefits and should be stimulated.

• Nearly all studies in this systematic review showed results in a positive direction.

• Methodological quality of the studies included was generally low.

• Future studies should aim to study mode shift with high quality designs.

Abstract

Introduction

A promising way to stimulate physical activity is to promote the choice for active modes of transport (walking and cycling). Over the past years, several interventions and policies have been implemented to stimulate this mode shift. However, information concerning the effectiveness of these interventions and policies is still limited. The aim of the present study was to systematically review the effectiveness of interventions designed to stimulate a shift from car use to cycling or walking and to obtain insight into the intervention tools that have been used to promote and/or implement these interventions.

Methods

Five databases were searched and articles published in English, Dutch, German, Danish, Norwegian and Swedish were included. Only studies that focussed on a mode shift from car use towards active transport in a general adult population, which were published in peer reviewed journals and which investigated effectiveness were included. Intervention tools used were categorized by using the model of Hoogerwerf & Herweijer, as either legal, economic (subsidy, reward system, penalty), communicative (written materials, behavioural tools) and physical tools (providing bicycles, providing better bicycle facilities at work, adjustment of the environment).

Results

Nineteen studies met our inclusion criteria. Studies included described work-place-based interventions, architectural and urbanistic adjustments, population-wide interventions, and bicycle-renting systems. Nearly all studies (except three) showed positive effects concerning a mode shift. Most of the included studies used more than one intervention tool and the tools used differed between types of interventions. However, information about the statistical significance of these results was often lacking and the study methodologies used were not of high quality.

Conclusion

Nearly all studies showed results in a positive direction. However, the quality of the included studies was mostly low and intervention characteristics were poorly described.

Introduction

Globally 5.3 to 5.7 million deaths from non-communicable diseases could theoretically have been prevented in 2007, if people who were inactive would instead have been sufficiently active (Kohl et al., 2012). Therefore, interventions effectively stimulating physical activity are of great importance. One way to stimulate physical activity is by influencing people’s choices regarding transport modes in favour of active transport modes (walking or cycling for the purpose of going somewhere). Several studies have shown that active transport has a protective effect on cardiovascular outcomes (Hamer and Chida, 2008) and is inversely associated with Body Mass Index (BMI), obesity, triglyceride levels and insulin levels (Gordon-Larsen et al., 2009). The Toronto Charter for Physical activity stated that transport policies and systems that prioritize active transport are amongst the best investments for stimulating physical activity since active transport is the most practical and sustainable manner to increase physical activity on a daily basis (Global Advocacy for Physical Activity (GAPA) the Advocacy Council of the International Society for Physical Activity and Health (ISPAH), February, 2011).

Stimulating active transport by enhancing the substitution of short distance car trips by walking or cycling (active transport) trips has generally become a common objective of transport policies (Ogilvie et al., 2004). In the recent past, at least three reviews investigating the effectiveness of interventions on a mode shift have been published (Ogilvie et al., 2004, Ogilvie et al., 2007, Pucher et al., 2010, Yang et al., 2010). Our study differs from the earlier reviews in a couple of ways. First of all, we included studies that report on effect measures either on both ends of the shift or effects within subject on changing transport mode. This included either or both walking and cycling at the one end of the shift and car use at the other end. Other studies were less strict and included studies reporting on either one of these effect measures. Second, we included studies irrespective of size. Whereas, others focused only on population-wide strategies. And third, we restricted our review to studies published in peer-reviewed journals as opposed to other reviews additionally including studies from grey literature. Although several interventions targeting a mode shift have been developed and published, information concerning the effectiveness of these interventions on inducing a mode shift is missing (Pucher et al., 2010). The aim of the present study was not only to gain knowledge about the possible effectiveness of interventions with the aim to induce a mode shift from car trips to walking and/or cycling, but we also tried to obtain insight into the intervention tools that have been used in these interventions. To this end, we systematically reviewed studies that have investigated the effects of interventions that aim to stimulate a mode shift from passive to active transport. The results of this study may help to develop suitable policies/interventions inducing a mode shift.