Lighting the way to road safety – a policy blindspot

With 9.4 fatalities per billion vehicle-kilometres travelled, NZ is 19th out of 23 OECD countries. This poor performance is generally explained by NZ’s low population density and lack of economic ability to spend enough per km of roading. Evidence supports insufficient road lighting and its low quality being a significant contributor NZ’s poor injury and fatality statistics. Analysis of a 2011 NZ Ministry of Transport survey indicates that the risk of death and injury from driving at night in NZ is 5.8 times greater than during daytime in contrast to international experience, which shows it is only twice the risk. Despite international research quoting improvements of up to 87% on fatalities with introduction of road lighting, apart from Canada, no evidence of a systematic strategic asset management approach was found for road lighting worldwide, and certainly not in NZ. Road lighting practice in NZ follows AS/NZS 1158 but this standard uses incorrect pavement reflectance values, does not use CIE’s recommended approach to Scotopic/Photopic ratios to correct for the eye’s reduced sensitivity to low intensity coloured lighting, and excludes LED road lighting. Modern LED lighting is a disruptive technology that will rapidly replace older technologies. It allows modern computerised approaches to integrate up to date crime and accident statistics with traffic flows, lighting levels from a commercially available Lux Mapping service, community feedback and events to provide night time improvements in crime, traffic accidents and community satisfaction. Using NZTA’s improvement factor from its Economic Evaluation Manual for reduction in night time fatalities and injuries for a national upgrade to modern road lighting shows a Benefit Cost Ratio of 10.3 without factoring in electricity or maintenance savings. This substantial benefit would make a significant contribution to the NZTA’s Road Maintenance Task Force initiative.