Loaded with laser sensors, blinking yellow lights, a GPS and digital camera, the little Mercedes Smart measures out bike lanes millimetre by millimetre for the bumps, potholes, tree roots and other imperfections that make riding on some bike lanes anything but smooth sailing.
“Previously, we only conducted a visual scan of bike lane surfacing,” says COWI Project Manager Brian Henriksen. “There are no requirements for how smooth a bike lane needs to be, and these types of measurements will allow local authorities to determine whether they are spending money on bike lane maintenance as wisely as possible.”
New methodSince cyclists experience the condition of asphalt differently than motorists, Henriksen was unable to use the International Roughness Index, the standard reference for measuring how smooth asphalt is.
Instead, he took a look at the asphalt from a different perspective and after a number of tests in 2004, he and a team from Dynatest came up with a new method known as the Bicycle Profile Index, which calculates overall smoothness by measuring the longitudinal profile in 2.5 centimetre sections.
The first measurements were made in 2005 in the city of Odense, which at that time was marketing itself as Denmark’s best city for biking and was looking for new cycling initiatives. The results were presented at the following Road Forum conference and were received positively by road engineers.
Since then COWI and Dynatest have measured the comfort of bike lanes in cities throughout Denmark, as well as Gothenburg and Stockholm, Sweden.
Biking helps reduce healthcare costs“Local authorities have a history of neglecting bike lanes compared to roads, but that is all changing,” Henriksen says. “More and more people are commuting by bike, and since biking helps reduce healthcare costs, it makes sense from an economic perspective. Beyond that, there is a general interest in making bike lanes a little nicer.”
The next step will be to ask Danish road authorities to approve the BPI. If that happens, it would make it easier to bring the technology to other cycling nations such as the Netherlands and Germany. It would also mean that contractors hired to build new bike lanes in Denmark potentially could meet a smoothness requirement in future tender documents. The ultimate goal for Henriksen is the approval of the BPI index as the world wide smoothness index for bike lanes.
By Christina Tækker
Published: 30.09.2010
