You might have heard the term “road diet,” which sounds like the dining habits of some asphalt-chomping ogre. And it kind of is! But what does it really mean? Here are four videos that explain exactly what transportation planners are doing when they turn space for cars into space for walkers and bikers—and why it’s good for your commute.


The videos are the work of urban designer Jeff Speck, who focuses on walkability in cities—we recently featured his campaign to get cities to move towards narrower 10-foot-wide lanes, which is safer and more efficient for everyone on the road. He collaborated with animator Spencer Boomhower to show how a road diet helps reallocate a street’s vehicular real estate, adding bike lanes, parking, and better pedestrian access.

You can watch as several different streets are transformed with only a swipe of paint, while Speck notes in the voiceover how these real world examples saw reduced crashes and no increase in travel times.


Here, the typical one-way street gains a two-way protected bike lane (called a cycle track) by pulling the parking towards the center of the roadway. This row of parked cars also protects people on bikes from the moving vehicles. Win-win!

Most American streets have four lanes of traffic, two moving in each direction. But reducing four lanes to three, with the middle lane serving as a permanent turning lane, gives planners enough room to add bike lanes. This is not only safer for turning cars but also prevents congestion from left-hand turns.


If a two-way street already has bike lanes, it’s not difficult to turn the same amount of space into a cycle track, which will encourage more riders to use it because they’ll feel safe. Again, simply moving the parked cars toward the middle of the road gives bikes plenty of room.


And finally, the typical too-wide street has 12-foot travel lanes which are not necessary in dense urban areas (unless cars are moving at freeway speeds—which they shouldn’t be). Simply narrowing the lanes to 10-feet each will create enough room to add a bike lane.


[Cupola Media via Momentum Magazine]