The concept is detailed in a 2009 research paper by Peter Furth, civil engineering professor and bike infrastructure expert at Northeastern University, who first came up with the idea.

The street markings, he wrote, can help provide the “feel” of a bike lane — even if there’s no room for one.

“It is a design option for a ‘just-in-time’ bike lane with the potential to offer bicyclists a level of safety and comfort that approaches that of an exclusive bike lane,” Furth wrote.

The “sharrows on steroids” are relatively unprecedented: Only a couple of other cities in the United States have tested them out.