The road ahead for lighting and safety

It’s time to challenge our presumptions about road lighting and road safety says an American road safety transport official who is visiting New Zealand in March.

“Lighting is presumed to improve road safety performance and so we’ve stopped our exploration of it,” said Dr John Milton, director of enterprise risk and safety management for the Washington State Department of Transportation in the United States.

Dr Milton said 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 we are shifting from standards-driven application to a performance-based, decision-making process.”

He 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 optimise road lighting cost-effectively to create conditions that result in the fewest crashes, 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.”

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

Dr 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 the application of digital LED lighting and control technologies at locations that have a higher than expected number of crashes, and considering the removal or reduction of lighting at locations that are unable to demonstrate sufficient benefit on its 7000-mile (11,200 km) highway system.

He said 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 said.

Dr Milton said 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,” said Dr Milton, “but we haven’t yet researched and developed the performance standards by which we can optimise the use of this new technology.”