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Roads, Highways & Infrastructure

The need is for a 7-8m underpass; the design is for a 23m wide underpass, wide enough to require columns in the middle supporting it. And for what? "Programmable space", which is architect-speak for "we don't even have an idea for what to do with this space at this point". If the underpass existed today with these dimensions, this would be an excellent design for how to use it. But it doesn't exist, and every metre of rail bridge costs millions. Why design three times what we need?
Agreed. In theory the idea of "programmable space" seems cool, but I have a hard time picturing it ever being useful. It would most likely end up being a shaded, cold windswept piece of nothing and the city will spend millions more 5 years later to try and improve it because it never gets used. Build a children's park or basketball court somewhere above ground where it's open and sunny.
 
I wonder how much of it might be future proofing (i.e., overbuild in case it has to be opened to vehicular traffic in the future).
I had that thought too, it's weird how similar the bridge span options are despite the vastly different practical requirement between all the options presented. Either the designers are building to assume a retrofit for vehicle access one-day or they have never walked through a successful, attractive and affordable pedestrian/cycling underpass before. Underpasses have real practical benefits for active modes transportation - it's significantly easier and more practical to descend gently 2.5 - 3m rather than do a silly switch back 5m into the air for a pedestrian overpass that takes 4x as long to travel the same distance.

As others have mentioned, I assume that the whole crux of the project from a deliverability and cost perspective is the structure to support the train - shorter spans, shallower depth of underpass is much, much cheaper than a wider spans and deeper underpass. The park and pathway infrastructure is great and would be a cool amenity on either end of the underpass, but costs nothing in comparison.

This is where I keep going back to weird engineering biases that don't seem to be impacted by the public debate on these types of projects. There's a shadowy design influence occurring that favours over-building and future-proofing. For example, a quick google suggests Netherlands has standards of 2.5m depth and active modes underpasses for specific reasons, one being cost. Here's a snip from a design website I think summarizes the things to think about when designing for an active transportation user, which aligns with shallow underpass depth requirements:
  • allow for lower gradient and/or shorter approach ramp for cyclist.
  • Let the cyclists see all the way through to the other side; to do this reduce the depth of the tunnel.
  • Make the approach to the tunnel straight from both sides. Make sure there are no dark corners obscured from view.
  • Let the cyclists utilize the speed they gain on the way down to get out of the tunnel quickly.
  • Walls leaning outwards helps to create a roomy feeling.
  • Consider making “windows” in the roof of the tunnel to allow daylight to enter sections of the tunnel.
  • Smooth curves in the construction elements instead of the traditional straight angles can also increase the perception of social safety.
11 Street SW plan proposed 3.0m - because our cyclists are taller than the Dutch? What could be the practical rationale for the extra depth and why is our standard 3.0m?

I will take a guess that an official answer will be about how the extra height has something to do with "comfort" or "perception" of safety in tunnels. But the list of design considerations above do the same thing, they just cost less. Plus if we are so concerned about comfort and safety I encourage transportation departments to turn that thoughtful design to literally all other parts of a car-dominated transportation system we have built, including many dangerous or inefficient designs literally blocks from this underpass.

0.5m difference between 11 Street SW and the Dutch designs sounds small but it's multiplicative all over in the design and use of the underpass. More work to construct, more slope for the future users forever. That kind of thing is baked-in for all these types of projects, active modes or car underpasses alike, that results in overbuilding, higher costs, and in the long run ultimately fewer underpasses because they all end up costing so much.
 
Agreed. In theory the idea of "programmable space" seems cool, but I have a hard time picturing it ever being useful. It would most likely end up being a shaded, cold windswept piece of nothing and the city will spend millions more 5 years later to try and improve it because it never gets used. Build a children's park or basketball court somewhere above ground where it's open and sunny.
The CPTED potential problems are massive, when it becomes a destination instead of a liminal space.
 
If building this underpass as an active modes crossing results in a need for the city to rebuild the 14 street and bow trail interchange than it's more than worth it
I'm open minded in having this as a park underpass, and remove vehicle access, but ONLY if the 14th Street interchange gets an overhaul, and it's direct access in all directions - as well improves sidewalk width for pedestrians and cyclists since it's extremely narrow currently.

Don't make vehicle access to the west beltline worse overall. If they go through with the active modes for 11th, do 14th at the same time.
 
The City is engaging on the rehabilitation of the Mission bridge. Would be great if they could widen the sidewalks and add separated bike lanes. Can’t count the number of times I’ve I walked or ran across this bridge and been met by a cyclist on the sidewalk.

 
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It needs serious rehab. The reno they did to it back in the 80s(?) ruined some really beautiful details it had. The beautiful light posts and railings come to mind. It’s currently hideous, so anything will be an improvement.
 
Working late on the Stoney Trail bridge (taken a few days before @Myles86's pics):

P1110462exp.jpg
P1110476exp.jpg
P1110516exp.jpg
 
Just gave me feedback on 11 st. With either option, I'd love to see elements of the 4th street underpass (also goes under 9 ave). Build the active option to appropriate scope and you could easily extend under 9 ave with money to spare. The 9 Ave intersection sucks.

If it's all modes, then the NB lane (and sidwalk) only could extend under 9 ave, while you could still turn SB off 9 ave. You'd have to double back on 8 ave to get to 9th, but the N-S flow and light timings would be way better. The challenge would be turning from 9 ave NB onto 11 st, but maybe there's a way to make it work.
 
Never thought the extension of Memorial Drive would ever happen, but I'm glad they're not adding ramps!

 
Never thought the extension of Memorial Drive would ever happen, but I'm glad they're not adding ramps!


Hope this will be a nice route for cycling - I usually go out to Chestermere on the canal path but there are no great options to loop back to the city - 17th ave south is kind of sketchy until you get to 52nd st and can switch to 16th ave south, going up to Conrich and back on McKnight is also kind of sketchy and also a pretty big lap for me.
 

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