The Visualisation of SiN in Edinburgh

Meade, Suzanne; Stewart, Kathryn; Maher, Mike

Abstract

Traffic safety has three primary dimensions: exposure (to risk), risk (of having a crash subject to a certain amount of exposure) and consequences (crash outcome e.g. injury type of a given crash). This paper focuses on two of those elements, exposure and risk.
Many countries, including Scotland, aim to increase the number of kilometres cycled or walked – thus increasing exposure – but the risk element can only change if conflicts between all users and their environment changes and existing safety problems associated with cyclists and pedestrians are reduced or removed.
The popularisation of the Safety in Numbers (SiN) effect in policy has led to a paradigm shift among planners and engineers in their approach to pedestrians and cyclists. The SiN effect proposes that increasing cycling or pedestrian activity leads to reduced accident risk. This is a relatively recent concept that it is increasingly popular in transport policy dialogue and among cycling and walking advocates in particular.
However, the co-existence of SiN and increased risk in low vulnerable road users (VRU) activity areas has also been identified by researchers. Therefore, while an aggregate SiN effect across a city or country may be evident, the effect may be weaker or absent throughout the region under consideration thus leaving high VRU risk areas unchanged. There is also still considerable debate surrounding the link between SiN and its causal effects that hinders evaluation.
This paper discusses the SiN theory in the context of exposure and risk in Scotland. Using a combination of GIS and multi-variate regression analysis to explore the spatial distribution of SiN, the research asks: ’who is safe in numbers?’ and ‘where?’. The spatial element of this research locates the strength or weakness of SiN across census Data Zone areas and explores the spatial distribution differences of risk and exposure in Edinburgh.
The spatial evaluation of risk and exposure is currently difficult especially for those who must implement current transport polices. This research aims to provide transport planners and policy makers with a visual tool to better understand VRU road safety and the SiN effect at a local level. Poor safety perceptions and outcomes are barriers to encouraging transfer to alternative modes of transport and poorly understood accident risk may limit future government investment in evidence-based safety improvement even if SiN appears to exist, at least at a global level. Considering the third element of road safety – outcomes – the magnitude of VRU injury and subsequent public health burden may continue to increase.

Citation

Meade, S., Stewart, K., & Maher, M. (2017, May). The Visualisation of SiN in Edinburgh. Paper presented at Scottish Transport Applications Research, Glasgow

• Presentation Conference Type: Conference Paper (unpublished)
• Conference Name: Scottish Transport Applications Research
• Conference Location: Glasgow
• Start Date: May 23, 2017
• End Date: May 23, 2017
• Deposit Date: Feb 27, 2020
• Public URL: http://researchrepository.napier.ac.uk/Output/1221921