In a perfect world motorists would not skim cyclists when overtaking. They would give them space, as explained by Chris Boardman in this industry-funded safety video. As we do not live in a perfect world academics and entrepreneurs have made proximity sensors to measure the distances that motorists give cyclists. These devices tend to be bulky and expensive so bike blogger Greycells created a small and cheap one. His "nearmiss-o-meter" may be crude but the parts were assembled for less than twenty quid.
His device is built from a £10 GPS, a £1.60 ultrasonic sonar and a £4 Arduino microcontroller.
"The aim is to provide enough information so anyone can build one with minimal knowledge," Greycells told BikeBiz (he prefers to stay anonymous).
"I'm sure there are many people better qualified than me, so I will release the initial designs – on github – as open source."
He hopes his sensor, and others inspired by his work, will be used for academic studies such as the Near Miss Project by Dr. Rachel Aldred and colleagues at the University of Westminster.
"My motivation is use data to try to influence UK transport policy," said Greycells.
His device is small, 50mm x 50mm x 40mm and can be easily transferred between bikes.
He has tested it – "on a local street on the way back from my local bike shop that is absolutely awful to cycle along" – and it works.
The idea for his nearmiss-o-meter came from this tweet: