Safe streets for cyclists? Quantifying the causal impact of cycling infrastructure interventions on safety
File(s)
Published version
Author(s)
Anupriya
Zhu, Xiaowei
McCoy, Emma
Graham, Daniel J
Type
Journal Article
Abstract
London’s Cycle Superhighways (CS) form a network of cycle routes connecting central London to outer boroughs, introduced in 2010 to promote cycling and improve safety. This paper examines their causal impact on cycling volume and safety using detailed road traffic and road safety data from the UK’s Department for Transport. To estimate these effects, we employ propensity score-matched difference-in-differences and panel outcome regression models, comparing two distinct infrastructure types: segregated and non-segregated CS. A key contribution of this study is the development of a novel safety indicator — the normalised collision rate — that accounts for changes in cyclist volume (exposure) while incorporating expected non-linearities in the relationship between collisions and exposure. Our findings indicate that non-segregated CS did not increase cycling volume but led to a substantially higher collision rate. This increase appears to be driven by a post-intervention surge in the proportion of new, inexperienced cyclists along these routes. In contrast, segregated CS effectively increased cycling volume without increasing collision rates. Further, an evaluation of a major segregation upgrade along an existing non-segregated CS route revealed a notable reduction in collision rates. These results highlight the crucial role of segregated infrastructure in not only encouraging cycling but also ensuring it remains a safe and viable urban transport option.
Date Issued
2025-09-01
Date Acceptance
2025-07-11
Citation
Accident Analysis and Prevention, 2025, 220 (1)
ISSN
0001-4575
Publisher
Elsevier
Journal / Book Title
Accident Analysis and Prevention
Volume
220
Issue
1
Copyright Statement
© 2025 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ ).
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/40743602
PII: S0001-4575(25)00254-4
Subjects
BICYCLISTS
Causal analysis
Cycleway investments
Demand
DEMAND
Engineering
Ergonomics
HEALTH
Heterogeneous impact
INJURY
LANES
Life Sciences & Biomedicine
PROPENSITY SCORE
Public, Environmental & Occupational Health
RISK
Safety
Science & Technology
SIGNALIZED INTERSECTIONS
Social Sciences
Social Sciences - Other Topics
Social Sciences, Interdisciplinary
Technology
TRACKS
Transportation
Publication Status
Published
Coverage Spatial
England
Article Number
108168
Date Publish Online
2025-07-30