Sunday, September 20, 2009

The evolution of bike cutouts

In the Previous Post, I documented the construction of the traffic island on MacLaren at O'Connor, which reinforces the "no going straight" sign while allowing cyclists to continue through. I also mentioned many design elements that the island incorporates. I'd like to explore the progression of previous generations of this type of facility in Ottawa.

One of the earliest versions of this type of traffic-shaping bulbout still around is on Lisgar at Kent, next to Hudson Park Phase I, shown here in August 2009. There are two "no through traffic; bicycles excepted" signs (one partially obscured by a "trucks turn right" sign), and there are two triangular concrete intrusions into the roadway on each side of the intersection, which together make it impossible to drive a car straight through the intersection without going over one of them. There's a bit of a dip on the left side of the near triangle, which appears to be an attempt to allow cyclists to go over it.

The next generation is a stand-alone island on the near side, on Cooper at O'Connor, next to Dominion-Chalmers United Church. People in the photo below are lining up for a Chamber Music Festival show in August 2008. The gap in the island allows cyclists to go through, while it's clear to motorists that they must turn right. Unfortunately, the "no parking" signs allow cars to block cyclists' access: in this case, the car had a disabled parking permit on the dashboard, allowing them to park in a "no parking" zone for up to three hours. The construction of this one was also pretty shoddy. It was originally just a perimeter of short concrete barriers filled in with asphalt, and the barriers would get knocked out of place, blocking the through channel. It looks like it's been repaired with a more permanent construction.

There is an even more sinister version of this on Kirkwood. As a traffic-calming experiment, they put in large bulbouts on alternating sides of the street, to slow motorists down with a zig-zag. (They tried a similar thing one year on Kent, but once the snow fell and you couldn't see the pavement markings, people just went straight, so they abandoned that idea and put bulbouts on only one side. This is why it's so hard to a safe distance up Kent when crossing westbound.)

So on Kirkwood, the roadway is designed for motorists to zig-zag and for cyclists to go straight along the edge of the road. There are a few big problems with this. As shown in the photo, cars can park in the way, blocking this route. Some park a lot closer, completely blocking the cutout. It also gets filled up very easily with gravel, leaves, sticks and other debris, which sweeper trucks obviously can't reach. Lastly, motorists on cross-streets don't expect to see anybody coming from that far away from the centre of the road. But once they built Kirkwood this way, they didn't have money to fix it, so it remains a treacherous facility for cyclists. Most cyclists I know stick to the left of the solid white line.

Another problem with the Cooper/O'Connor generation of traffic islands is that the gap for cyclists is too narrow. Too narrow to allow some wide cargo bikes, but more importantly, too narrow to allow snowplows to pass through. So instead the cycling facility becomes a snow dump, as shown here in January 2007:

The most recent island at MacLaren and O'Connor (the subject of the previous post) was built wide enough for sidewalk plows to pass through, as shown in this photo from Friday:

However, that doesn't mean they always do clear it, as shown in this shot from last November (just before the transit strike), which was prevoiusly posted in Centretown, Darkly, Under Snow:

Of course, the downside of having a wide-enough cutout is when an idiot taxi driver comes along thinking his car will fit. This driver's tires got stuffed and the tire sidewalls rubbed against the curbs as he struggled to drive through.

There's one more in Centretown, on McLeod at Bank Street. While it's dug up now as part of the Bank street reconstruction, here's what it looked like last December. You can see it's a long triangle with no cutout for cyclists.

While the signage allows cyclists to go straight or left, doing so was always tricky, because there wasn't much clearance in the opening, and you had to jog around. Right-turning motorists behind you had to be patient while you waited for both directions of traffic on Bank to be clear, while they would only need the nearest lane to be clear for their forced right turn.

In preparation for Bank Street being closed for reconstruction this summer, they removed the triangle in April to allow for through traffic. For reference, the Metropolitan Bible Church is to the right of the shot out of frame, and the Tommy & Lefebvre site is across the street on the left.

Back in November, it looked like there weren't going to be any cutouts along Bank, so I fired off some e-mails pointing out that one would be ideal at this location. In April, I was sent the following drawing showing how a bike cutout will be installed at this location. It matches well with the angle at which McLeod crosses Bank.

In general, curb bulbouts reduce the distance between sidewalks, thus reducing pedestrians' exposure to motor traffic while crossing, and they also calm traffic by reducing the lane width at intersections. These ones shown in this post have the added function of discouraging unwanted behaviour, in this case, going straight through an intersection. But there can be side effects, some of which aren't apparent until they're installed and in use. Bulbouts must leave enough room for a shared motorist/cyclist lane (minimum 4.25 metres), and if cyclists are allowed through them, there must be a track that is clear of debris and easily navigable. With each iteration, new things are tried and past failures are worked out of the design, but these are painful lessons, as the failed designs can stick around for years until the entire road is rebuilt.

Other examples of road design evolution through experimentation include concrete crosswalks and roughened crosswalks, both of which help to delineate pedestrian zones. The first kind does it visually, and the second kind audibly (car tires going quickly over it make a buzzing noise). The Mid Mod has already shown the latest iteration of the zebra crossing in front of City Hall; I might do a post sometime down the line on crosswalks at intersections.


  1. I do know of at least two more in Centretown. There's one at on Cooper at O'Conner, and one more on Percy at Flora, of all places. The latter isn't quite the same, though: it allows traffic through, but there's no bulb forcing cars to turn.

  2. Hi Dave, the Cooper/O'Connor one is in the post above. It's just buried in snow. The Percy/Flora one is to direct northbound cyclists off of Percy at the end of the two-way pathway, but you're right that it serves a similar purpose. I hadn't thought of it that way.