Wednesday, January 8, 2014

Peds on Weds: Toronto-style sidewalks part 1

For quite some time now, I've wanted to do a thorough writeup on what in Ottawa traffic-geek circles is referred to a "Toronto-style" sidewalk design. People love them and hate them, for reasons that I'll discuss over the next three weekly pedestrian-themed "Peds on Weds" posts, starting here.

The sidewalk seen below is an outstanding example of what people I know call a "Toronto-style sidewalk". I've no idea what people in Toronto call them, and for all I know the title might be apocryphal. The term refers to is a wide, flat surface for pedestrians, and the crosspath is ramped only to the minimum extent required for motor vehicles to get up to the height. This example is on the east side of Bronson looking north from Somerset to Cooper Street in August 2013, not long after it was installed. Pardon the spray paint markings:


The benefit is for pedestrians, but this is anathema to the car-centric roadbuilders who install them, as Eric Darwin described in a West Side Action post about the installation of the sidewalks on Bronson:
"I talked to the project / concrete foreman on the site [Bronson west side, north of Gladstone]. I complimented him on keeping so much of the walkway level. He, however, was much more interested in pointing out how gentle the motorists’ slopes were, so there wouldn’t be much of  bump for them."
The ramp is what gives the design its official name in the City of Ottawa, which has been the official standard in the City of Ottawa since June 2006: the "Ramp Style Vehicle Access Crossing" (being a traffic department term, naturally the title refers to its relationship to vehicles rather than to pedestrians or sidewalks). There is a gradual 2% grade over the flat part of the sidewalk to drain water away from the road (2% is not as steep as depicted here) which must be at least 1.05 m wide, and the ramp is 75 cm wide, assuming a curb height of 12.5 cm:


This is in contrast to the previous standard, approved in 2002, which didn't need a specific name since there was no previous standard to distinguish it from. I've variously heard different terms for it, but "wave", "wavy", or "roller-coaster" sidewalks are the ones that best get the point across. Though I've also heard non traffic geeks (a.k.a. pedestrians) call them "ramp" style. This one is in front of the Somerset Gardens condo development at 138 Somerset, in a photo I took in Spring of 2012:


This example typifies the primary features of the "wave" style sidewalks: the entire sidewalk drops down, not just at the road surface ("front of sidewalk") but also at the back of sidewalk. Despite the total-drop, the entire width of the sidewalk slopes to the side too. As a result of this obvious accommodation of the car, pedestrians get two additional design features: wet boots and wet bums (from water pooling across the sidewalk and ice accumulating on the slopes of two dimensions).

One of the rotating header images on the Walk Ottawa website shows a series of wavy curb cuts on an apparently new sidewalk in a true "roller-coaster" fashion.

Here's a technical drawing that shows the primary design parameters of the 2002 approved design:


I won't go over all the blurry details, but there's a 2% drainage slope towards the curb across the pedestrian's walking path, which can increase to 6% at driveways. It almost certainly will, since the ideal height at the curb is 15 cm, 2.5 cm higher than the height given for the 2006 standard. To mitigate this, though, the design drops the back of the sidewalk at curb cuts as well as the front—but then permits a slope of up to 8% along the sidewalk!

If you didn't follow all those numbers, the upshot is demonstrated on Florence Street in the next two photos, taken in a February 2011 thaw-rain-freeze cycle like the one we just got this week. First the rain drains over the entire width of the sidewalk:


Then it freezes solid:


Ironically, the ice covering the dips in the sidewalk there appears to make a more level walking surface than the submerged concrete.

The more typical situation is like here on the south side of Lisgar, just west of Elgin, where the thin layer of ice follows the slopey surface of the sidewalk. To be fair, this stretch of sidewalk was likely installed long before the 2002 standard came into force, but the slope is so extreme that you'd slide right off your feet if you tried to walk over that ice (not to mention that the photo is slightly askew in a way that makes the sidewalk seem more level than it really is)!


I don't have many photos of Toronto-style sidewalks in Centretown, in part because there aren't many examples: our reconstructions since 2006 have mainly been on main streets (e.g. Somerset, Bank, Bronson) with more complicated design parameters. For example, on Somerset between Bank and O'Connor, the sidewalks are very wide to reflect the pedestrian-oriented atmosphere, allowing the "vehicular access ramp" to be entirely outside the travelled portion of the sidewalk:


Elsewhere in Centretown, there have been a few residential streets redone in the Golden Triangle, including Delaware (which was one of the streets used for the pilot in 2006 and had sub-standard width sidewalks installed—more on that next week) and Park Avenue. Since I tend to bike whenever I go to the Golden Triangle, I unfortunately have few photos of the Toronto-style sidewalks there, such as this one at 77-81 Park Avenue:


The theory with the Toronto-style design is that the top of the sidewalk always remains flat, so that it is less likely to become puddled, and even if it does freeze over at least you're walking over a flat icy surface rather than a slanted icy surface. Here's Park Avenue again in the wintertime:


That's the theory, at least...

TO BE CONTINUED:

Today's post was a description of how Toronto-style sidewalks are supposed to work and some examples of them working well. As many of you will probably be eager to comment, there are plenty of examples of this style of sidewalk that don't work.

Next Wednesday, I'll talk about some problems with give a more technical history of the Toronto-style sidewalk design. The following Wednesdays, I'll talk about some problems with the Toronto-style sidewalk design, then I'll go over some alternative sidewalk designs from the past and present. Part 3.

[Tune in on Wednesdays at noon for a new pedestrian-themed blog post. View the Pedestrians label for previous Peds on Weds posts]

3 comments:

  1. Toronto-style sidewalks are also a nice visual deliminator of pedestrian space vs. car space; with a slope up to access driveways, it keeps the space for foot traffic separated visually from that for car traffic; with the slope down to accommodate cars, it makes it more like pedestrians are entering car space, when really the cars are supposed to treat sidewalks like stop signs. Higher ramps to access driveways would probably also result in slower car speeds crossing the sidewalks as well, to avoid bottoming out.

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  2. The Toronto style sidewalks could be much improved if there was less slope to the street. Why does the curb dip have to be flush with the street asphalt? Can't all those horses inside the car hood propel it up over a 1" curb, which would then reduce the slope on the rest of the sidewalk? Better yet, use the rolled curb at driveways and the high curb between driveways, so cars do all the climbing at the rolled curb.

    And why, oh why, does the city slope the ENTIRE extra-wide walk zone on traditional main streets, when they are redone? Com'on, if the sidewalk is 10' wide the city slopes all 10' of width down to the curb, instead of just the 18" to 24" closest to the curb (where the lamp posts, signal posts, trees, bollards, and other stuff is put, and thus is out of the primary walking path). This excessive sidewalk subservience to the crossing motorist is visible on West Wellington, Preston, Somerset ... the litany of horrors goes on and on.

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    Replies
    1. All those are questions I plan to cover in next week's instalment (not necessarily answer them but at least I'll repeat them...). You suggest a couple variations that I hadn't encountered but which I'll try my best to incorporate.

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