Swedish scientists have tested different road surface compounds to give cyclists a softer landing
A bouncy road surface could help Tour de France riders nervous of the multiple crashes that are sadly common as twitchy riders settle down during the race’s hectic first week.
Part of the problem can be blamed on the solid asphalt laid on top of most roads to withstand the pounding of motor traffic. It is unforgiving and can give cyclists a hefty blow when they take a tumble, not to mention the road rash grazes that skin arms and legs.
Bicycles, though, don’t need such a sturdy surface because they are many times lighter than motor vehicles. So now safety scientists are testing friendlier solutions that will be good for cycle lanes and paths while being better at absorbing impacts. They reckon they will reduce the chance of riders getting hurt.
The study by a Swedish research team has taken a leaf out of the children’s playground design manual and added rubber to the mix that makes up the blacktop.
They have experimented by building four short cycle paths, each with different ingredients to see which is best.
Just in case
Interestingly, the trials were done at AstaZero, a test centre more commonly used by the world’s car-makers to prove their latest safety technologies.
It would be difficult (and unethical) to find a cyclist willing to deliberately fall onto the rubbery cycle paths to see how bouncy they are, so the scientists used equipment to measure the amount of cushioning the soft surfaces can give.
Then they put the data into a computer simulation of a human head striking the same surface. It showed that three of the four rubbery mixtures can cut the risk of head injury significantly.
They also assessed the friction of the new cycle lane materials to make sure they give bicycle tyres good traction. They found it meets with British legislation and doesn’t increase the risk of rotational forces, the twisting movement that’s sometimes blamed for brain damage on impact.
The rubber displayed another advantage compared to traditional bitumen and concrete roads – it tends to prevent ice from forming in cold weather and so reduces the chances of skidding.
The scientists, whose research was backed by Swedish government funding, made one final flourish by adding phosphorescent silica to one of the rubbery mixtures.
So not only was their experimental cycle lane softer and safer for cyclist, in hours of darkness it also glowed softly.
Thought about going electric?
New functional pavements for pedestrians and cyclists by V. Wallqvist, G. Kjell, E. Cupina, L. Kraft, C. Deck & R. Willinger is published in Accident Analysis and Prevention, online 18 May 2016.
Max Glaskin is an award-winning freelance journalist who tweets about cycling and science as @CyclingScience1.
He is author of Cycling Science (published by Frances Lincoln UK, Chicago University Press USA, and seven other languages).