Having a plan to “accommodate bikes” isn’t as simple as drawing lines on a map. Often it involves tradeoffs between parking, travel lanes, and sidewalk space. But particularly in places where people will be bicycling, striping bike lanes can actually reduce congestion on the street.
Here’s a neat chart from a 2013 study (via People for Bikes) that models the effects of bicycles on travel time on streets with and without bike lanes:
And here’s another chart, modeling different street designs scenarios:
Here’s the takeaway from People For Bikes:
When bicycle use rises but cities don’t add bike lanes to put the new bikers in, traffic congestion actually gets worse.
The study, co-authored by Gosse and his professor Andres Clarens, used a traffic simulation to compare four theoretical two-way, two-lane streets:
A) One where bicycles were 1 percent of traffic (about the level of many U.S. cities) with no bike lanes.
B) One where bicycles were 1 percent of traffic with bike lanes.
C) One where bicycles were 10 percent of traffic (about the level of Eugene, Oregon, or Boulder, Colorado) with no bike lanes.
D) One where bicycles were 10 percent of traffic with bike lanes.
The street with the most congestion? It wasn’t Street A, which represents so many in the United States today.
The most congested street was Street C.
As Andy pointed out earlier this week, Ramsey County is debating whether to stripe bike lanes on Cleveland Avenue in Highland Park right now. To me, the lesson seems to be that ignoring bicyclists (with sharrows, or nothing at all) does not make them go away. In fact, might make traffic even worse…
My favorite stpaul.gov/open comment so far (and there were A LOT of great ones):
“It is nearly impossible to get a good traffic flow on Jefferson. It has a bike lane going right down the middle of it!!”
I dunno, 99% of the time I’m slowed down by motorists and with 10% bike traffic would it really be less congested if that 10% were to all drive a big motorized SOV instead? But then in my case I’m riding a real bike and moving at around 20 MPH: I’m not going at a leisurely pace. I think the biggest problem are the should-be travel lanes where cars are allowed to just stop in the middle of the lane and yet it’s accepted by motorists; that’s what’s causing way more congestion, not the slow bikes moving the same speed as a jogger. At least they’re moving, unlike cars in the parking lanes where traffic could instead be moving.