On Tuesday, the traffic circle on 35th Avenue and Raleigh Street in West Highland was already calming car speeds a day after Denver Public Works installed it. The streets department will install two more this week at Newton and Julian streets in hopes of scaling down the speedy road into a neighborhood street fit for walking and biking.

The interventions are technically temporary. The idea is to test them out and show the public why they’re a good idea. When they prove to calm driving speeds — they will — DPW will install permanent circles made of concrete.

These things are the first of their kind in the city and represent a win for safer streets. At about $11,000 a pop, they’re the kind of quick, inexpensive treatment Denver needs more of. Mayor Michael Hancock said as much on Twitter.

“We understand that small fixes like this can make a big difference to a neighborhood,” Hancock wrote.

But it’s been well over two years since Hancock committed to Vision Zero and we can only point to a couple of similar traffic-calming projects: Some pedestrian islands on 26th Avenue and fixes to the intersection of Colfax, Park, and Franklin.

The traffic circles have been in the works since at least 2015. They’re part of a drawn-out planning process to make 35th a legitimate bikeway that included a 42-page “feasibility study” — and the bikeway won’t be done until next year [PDF]. DPW Executive Director Eulois Cleckley says he has his eye on speeding these things up.

Meanwhile more people walking and biking have already died this year than in all of 2017. The city needs this kind of intervention in hundreds if not thousands of locations across the city, not just once a year on one street.