Background Improving the environment including the streetscape can encourage walking and cycling, which could impact health. However, more evidence on the effectiveness of streetscape changes on travel patterns is needed. The aim of this study was to measure the impact of modal filters implemented as part of the Low Traffic Neighbourhoods scheme (LTNs) in Southwark, London on driving, walking, and cycling levels.

Methods Three neighbourhoods in Southwark (Brunswick Park, North Peckham, and East Faraday) introduced modal filtering measures by installing planters and bollards which restricted access to motorized traffic but not to pedestrians and cyclists. Intervention areas were matched to control neighbourhoods with no street changes. Data were collected by Southwark Borough Council in all neighborhoods at baseline and one-year follow-up on daily traffic, pedestrian, and cycling counts and traffic speeds using automatic counters and video monitors. Each neighbourhood was divided into ‘project’ and ‘boundary’ streets to capture potential displacement of traffic on streets adjacent to intervention streets. Data were further separated by weekday and weekend days. We used a difference-in-difference analysis to estimate the effects of the LTNs by calculating the change in travel behaviours in intervention areas relative to control areas.

Results Daily traffic counts decreased on ‘project’ streets in the intervention areas relative to controls by 860 (95%CI 409, 1312) in Brunswick Park and by 937 counts (328, 1546) in North Peckham. Traffic also decreased in East Faraday, but confidence intervals were wide and non-significant. Across all three intervention project areas, traffic speeds decreased. Although there was an uplift in traffic levels on ‘boundary’ streets, confidence intervals were wide and crossed zero. In general, there were no significant changes in daily walking and cycling counts, except for a reduction of 32 cyclists (3, 61) in North Peckham.

Conclusion Findings from this study demonstrate that modal filters can reduce traffic levels and speeds. However, introducing these measures alone may not increase levels of walking and cycling. Future research may consider longer-term and other health-related impacts of these schemes such as changes to air and noise pollution.