Starpath: a spray-on coating that makes paths glow in the dark A spray-on coating that makes ordinary pathways glow in the dark could be the future of street lighting, absorbing UV rays during the day and expelling them at night as a soft blue glow. Named Starpath, the process has been invented by the UK-based Pro-Teq and can be applied to pretty much any solid surface including tarmac, concrete and wood. The application is carried out with specially-designed spraying equipment, beginning with a polyurethane base and aggregate (a rocky, sandy mixture that forms the new path-top) followed by the biolmuniscent material itself and a polyaspartic topcoat that seals the whole thing together. "It's something that's very environmentally sound, there's no ongoing energy costs," says Pro-Teq owner Hamish Scott. And we're also sorting out the problem of pathways that have come to the end of their lifetime. Although the process couldn't replace the need for bright lights on busy streets, they're perfect for areas with reduced footfall - especially as these places are also where councils are likely to try and cut costs by eliminating lights all together. Scott describes the finished effect as remarkably subtle: "There's no light pollution from it at all. People walk down it and cycle down it quite happily and they don't even know they've been on it. If it's a light evening then you'll see where you're going on the path, and if it gets very dark it'll glow brighter. The invention is currently being trialled in Christ's Pieces park in Cambridge, where 150 square metres of path were converted, ready for use in under four hours, and Scott believes that Starpath has a global potential. We're getting a massive response from developing countries where power supplies are very hit and miss. In those scenarios it's going to be extremely handy - and not just for pathways or cycleways; there's also the potential to roll this out down hard shoulders and central reservations. The process currently works at around £70 per square meter (although this does include the price of repairing the path) and Pro-Teq is working on an upgraded process that can be applied to underpasses - so if walking on a Starpath isn't your cup of tea then walking through a Startunnel might be.