DSC_0124.JPG A city official in Aarhus, Denmark attaches a tag to a bike wheel. ID-Advice

Bikers in Aarhus, Denmark could soon breeze through traffic lights without ever slowing down. 

The trick: special barcoded tags that attach to bike wheels and turn stoplights green when cyclists approach an intersection.

Aarhus has tested about 200 bike tags in the past year, Louise Overgaard, who works on the project, tells Tech Insider.

Currently, only one intersection has the system. If the trial is successful, the city may invest in 1,000 more tags and install the systems in additional neighborhoods.

"We need to decide on a political level to expand to other junctions," Overgaard says. "The most important thing is that cyclists feel there is a safe space for them."

The bike tags work with a little help from RFID barcodes, the same types of barcodes used in grocery store checkout lines. DSC_0165.JPGA bike tag.ID-Advice

When cyclists ride past an intersection, a nearby scanner detects the tag. It then stops incoming car traffic and turns the biker's light green.

The cyclist would never even need to stop.
DSC_0150.JPGA bike tag reader.ID-Advice

The tags are part of a larger project from the European Commission, called "Radical," which works to develop city tech services, like apps that track CO2 emissions and offer safe bike routes. Five cities across Europe currently participate: Aarhus, Denmark, Athens, Greece, Issy-les-Moulineaux, France, Genoa, Italy, and Cantabria, Spain.

Overgaard says the other four European cities are interested in the tags, although there aren't any concrete plans yet.

"Every city could use it," she says.