Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

The ‘safety in density’ effect for cyclists and motor vehicles in Scandinavia: An observational study

Johnsson, Carl LU ; Laureshyn, Aliaksei LU orcid ; D'Agostino, Carmelo LU orcid and De Ceunynck, Tim (2020) In IATSS Research
Abstract
Safety in density (SID) potentially explains the safety in numbers (SIN) phenomenon by positing that ‘the SIN effect can be reproduced simply through encouraging behaviour that leads to the formation of higher-density cyclist groups’. The study further explores this hypothesis using event-based exposure, queues and groups of road users. Using three different definitions of encounters between road users, these were manually counted at signalized intersections, and their relationship to traffic volume was assessed. Based only on the frontmost motor vehicle in a queue and one cyclist among the several passing in front of that vehicle, the results show a less than linear relationship between meetings and trafficvolume. An in-crease in the number... (More)
Safety in density (SID) potentially explains the safety in numbers (SIN) phenomenon by positing that ‘the SIN effect can be reproduced simply through encouraging behaviour that leads to the formation of higher-density cyclist groups’. The study further explores this hypothesis using event-based exposure, queues and groups of road users. Using three different definitions of encounters between road users, these were manually counted at signalized intersections, and their relationship to traffic volume was assessed. Based only on the frontmost motor vehicle in a queue and one cyclist among the several passing in front of that vehicle, the results show a less than linear relationship between meetings and trafficvolume. An in-crease in the number of cyclists entails a general increase in cyclists passing in front of each motor vehicle, and an increase in motor vehicles increases queue lengths. However, crash data from the Swedish accident database (STRADA) show that it is exceedingly rare for multiple cyclists to be injured in the same crash. Together with results from a crash-encounter model, this suggests that the SID hypothesis may help to ex-plain SIN (Less)
Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Contribution to journal
publication status
epub
subject
in
IATSS Research
publisher
Elsevier
external identifiers
  • scopus:85090748696
ISSN
0386-1112
project
In-Depth understanding of accident causation for Vulnerable road users
language
English
LU publication?
yes
id
90878f1a-3b32-4309-b379-8a389aa35a31
date added to LUP
2020-09-30 12:08:46
date last changed
2022-04-19 00:55:17
@article{90878f1a-3b32-4309-b379-8a389aa35a31,
  abstract     = {{Safety in density (SID) potentially explains the safety in numbers (SIN) phenomenon by positing that ‘the SIN effect can be reproduced simply through encouraging behaviour that leads to the formation of higher-density cyclist groups’. The study further explores this hypothesis using event-based exposure, queues and groups of road users. Using three different definitions of encounters between road users, these were manually counted at signalized intersections, and their relationship to traffic volume was assessed. Based only on the frontmost motor vehicle in a queue and one cyclist among the several passing in front of that vehicle, the results show a less than linear relationship between meetings and trafficvolume. An in-crease in the number of cyclists entails a general increase in cyclists passing in front of each motor vehicle, and an increase in motor vehicles increases queue lengths. However, crash data from the Swedish accident database (STRADA) show that it is exceedingly rare for multiple cyclists to be injured in the same crash. Together with results from a crash-encounter model, this suggests that the SID hypothesis may help to ex-plain SIN}},
  author       = {{Johnsson, Carl and Laureshyn, Aliaksei and D'Agostino, Carmelo and De Ceunynck, Tim}},
  issn         = {{0386-1112}},
  language     = {{eng}},
  month        = {{08}},
  publisher    = {{Elsevier}},
  series       = {{IATSS Research}},
  title        = {{The ‘safety in density’ effect for cyclists and motor vehicles in Scandinavia: An observational study}},
  year         = {{2020}},
}