Literature review

As part of Stage 1 of the study, Edinburgh Napier University’s Transport Research Institute undertook a Literature Review of peer-reviewed and grey literature addressing the perception of speed and speeding in rural settlements bisected by main routes for motorised transport. The full findings of the Literature Review are presented in Appendix C.

The Literature Review examined existing research to assess if perceptions of speed and gap acceptance have been quantified in similar environments to strategic roads in Scotland. The literature review included research into “self-regulation” of non-motorised road users, as well as the wider variables. 

Following post-COVID-19 resumption of the project in summer 2022, the literature review was updated to reflect any additional publications.

The key findings of the Literature Review are presented below, including the assessment of how strongly the evidence supports the stated finding.

Literature Review Findings

• There is a paucity of research addressing resident ‘roadside’ perceptions of traffic speed, not least in rural settings. (Strong)
• Research and public policy within the past few decades have focused on drivers, thereby neglecting pedestrians, e.g. older pedestrians and their travel requirements. (Strong)
• Healthy older pedestrians find higher-speed traffic challenging to road crossing and this relates both to their attention and speed of walking. Moreover, at higher speeds, pedestrians tend to accept smaller time gaps, i.e. they initiate riskier crossings. Adding cognitive decline and diseases such as Alzheimer’s or Parkinson’s and the road crossing task on such roads is much harder and may not be attempted. (Strong)
• Perceptions of vulnerable road users of high traffic volume and the traffic speed as ‘fast’ also perceived a higher proportion of road traffic being HGVs. (Medium)
• "Self-explaining roads" focuses on functionality, homogeneity and predictability to make roads safer. Roads designed in this way are also more user-friendly and are designed for pedestrians and cyclists as well as motorists. It combines objective data with resident speed choice ratings. (Medium)
• For cycle users being overtaken by motor vehicles, lateral clearance does not appear to be the only factor that influenced rider’s risk perception, although current standards are only related to it. A combined factor of lateral clearance, vehicle type and vehicle speed had a more significant correlation with the perceived risk. High-speed roads may also present a greater risk to cycle users. (Medium)
• Research specifically addressing traffic and health and quality of life finds that close proximity to main road traffic reduces this, not least through reduced walking, although there is no evidence regarding impacts of speed of traffic per se. (Medium)