Poorly designed road lighting can increase the risk of accidents, yet ‘lighting is presumed to improve road safety performance and so we’ve stopped our exploration of it,’ says an American road safety transport official who is visiting New Zealand in March.

Dr John Milton, director of enterprise risk and safety management for the Washington State Department of Transportation in the United States, says standards-based application of lighting design is slowing the evolution of lighting to optimise road safety, and in the interests of road safety that needs to change.

In Washington State, the Department for Transport is shifting its practice from standards-driven application to a performance-based decision-making process.

Milton says much of our road lighting technology is now 40 years old and so is our understanding of lighting and ‘road crash potential’. New adaptive lighting technologies will enable us to improve road lighting in an affordable way, creating safer roads – but we need to understand how to do that.

‘Think where we’d be with 40-year-old technology in our cars – with lap belts, drum brakes and no airbags. That’s what we’re doing in road lighting. We need to continue research so lighting can evolve.’

Milton is a keynote speaker at the ‘Road Lighting 2015: Smart City Investment’ conference on 9-10 March at the Langham Hotel in Auckland. He is responsible for the identification, assessment and mitigation of all transport risks for the Washington’s 7 million population, and will present findings from the state’s research programme incorporating road crash analysis, the effect of road lighting and driver reactions.

Milton says the challenge today is to optimise spending on road safety techniques, such as road lighting, and to apply its use where it will have the most benefit. Using statistical analysis, Washington State is targeting locations that have a higher than expected number of crashes and applying LED and control technologies to those areas. It is also considering removing or reducing lighting at locations that don’t demonstrate sufficient benefit on its 7,000 mile (11,200 kilometre) highway system.

He says while well-designed road lighting can reduce road crashes, poorly-designed road lighting may increase accidents, for example by causing reflective glare that makes road markings invisible in wet weather conditions.

Location of lighting is also important. Lighting is likely to be of greater benefit on roads where there are lots of intersections and road access points, such as driveways, and to be of less benefit on stretches of double-lane highways without intersections, he says.

Milton says Washington State Department of Transportation had ramped up its research on road lighting in the past three to four years since the advent of new technology LED lighting and control systems.

‘The energy, cost-efficiency, flexibility and greater visibility that LED affords make this a very beneficial technology, but we haven’t yet researched and developed the performance standards by which we can optimise the use of this new technology.’