Removing Through-traffic on Minor Roads Reduces Road Danger at Junctions with Surrounding Major Roads

We tested the hypothesis that road safety improves at junctions between minor roads and major roads if the minor roads are modally filtered to remove through traffic. We did this by using police-reported casualty data (2012–2024) to examine the effects of 113 Low Traffic Neighbourhoods (LTNs) implemented in London between 2015 and 2024. Our findings supported our hypothesis: LTN implementation was associated with a 14% reduction in total numbers of casualties at junctions between newly filtered minor roads and surrounding major roads (95% CI: -21% to -8%). This effect was generally consistent across casualty injury severity, casualty travel mode, and the presence of traffic-light controlled signals.