Highways in Canada

[Dado]

Originally Posted by go_leafs_go02

I like A4 better than B4 because it first of all doesn't seem as dangerous as vehicles flying off the freeway don't enter a large loop where they can tip over.

Seems like a safety feature to me: it forces drivers to actually SLOW DOWN when exiting the freeway because the consequences of not doing so are so high to themselves. That would apply most to the B2 of course which completely eliminates any possibility of a high speed offramp.

The loop ramps in an A4 come from a lower speed road or highway.

The loop ramps are the worst aspect of the design.

The second thing is that a B4 requires left turns off a major roadway, in which some major signal timing changes are needed or queues will back up across the bridge structure and through the other signal on the other side of the interchange.

What a tragedy.

I wish BC would use more A4 interchanges, they've just introduced one at Highway 1 and 176 Street that works fantastically, and I hope to see additional introduction in the future.

I wonder if this cyclist here will agree with you when he has to cross the traffic entering the loop ramp...

Count yourselves lucky that BC doesn't use more of them. I sure wish Ontario wouldn't but unfortunately for us the MTO has a love affair with this bad interchange design - the entire province is littered with the things.

They're a menace to pedestrians and cyclists, which in this day and age ought to be enough to remove them from contention outright, but then the MTO has never really cared for any kind of transport besides cars and trucks.

Besides that, they're illogical (turn right to turn left?), they clog up the right hand lane with would-be freeway traffic ahead of the interchange where it gets to mix it up with cyclists and buses, they're wasteful of land and require longer spans over the freeway than diamonds, the average driver can't use the loop ramps worth a damn to accelerate in lanes which are artificially short due to presence of the second onramp, they require a ridiculous amount of effort to clear the ramps of snow in the winter (think about the route snow plows have to take to clear all six ramps compared to a diamond) and buses using the freeway can't make use of them in an unmodified state for a bus stop like they can with a diamond.


Overall, the A4 Parclo is the worst standard interchange design in existence after the full cloverleaf. Even the A2 is better since the loop ramp is usually tied into an intersection forcing cars to make a proper slow speed right turn onto it and it will have a longer acceleration lane on the freeway itself (since the other onramp doesn't exist) so even if you have the misfortune to be stuck behind someone who can't accelerate on a curve at least you have a reasonable chance of being able to get up to speed on the rest of the merge lane.

I just cannot fathom why highway engineers in general and those of the MTO in particular are so infatuated with this horrible interchange design.

The best is probably the diamond, with the B2 being a respectable second.

[sonysnob]

Originally Posted by Dado

I just cannot fathom why highway engineers in general and those of the MTO in particular are so infatuated with this horrible interchange design.

They use them because most of what you have written is BS.

[Dado]

Originally Posted by sonysnob

They use them because most of what you have written is BS.

Really? Why don't you put some real effort into your reply and disprove each point in turn.

I was nearly killed cycling over the Queensway in Ottawa on Moodie Drive by a motorist who was turning onto the Queensway via the loop ramp. The design encourages motorists to start acting like they're on the freeway when they're still on the arterial.

Here's what it looks like now (it has been changed (widened) to add a bike lane, amongst other things; back then the onramp lane didn't start until much closer to the ramp):
http://maps.google.ca/maps?f=q&hl=en&geo...vqGOnwafA4W-ffWTtA&cbp=12,351.69,,0,9.71

In what universe is this a good design?

The design is a menace to cyclists. It's only slightly less worse for pedestrians, but only because they can stop on a dime.

The loop ramps should all be removed and the interchanges converted into diamonds. It would be a lot safer.

[go_leafs_go02]

Originally Posted by Dado

The loop ramps should all be removed and the interchanges converted into diamonds. It would be a lot safer.

Find me one urban diamond interchange that works well from a capacity standard in peak period, as that involves 4 separate left turn movements, while a Parclo A4 involves only 2. Let's see how the Linc in Hamilton worked if all interchanges were diamonds.

Unless you're talking about the new diverging diamond interchange, which I think are fantastic, the traditional diamond is pure crap expect for low volume situations.

Here's a perfect example of what should be done for all sidewalks/bike lanes crossing over a loop ramp, make them cross at a 90 degree angle, and require them to yield to vehicles. I've riden through there, and the line of sign is fantastic, drivers will see you, slow down, and let you cross with no issues. Safety was not a risk in any way to me.

http://goo.gl/maps/Atu5H

[Wharn]

Originally Posted by go_leafs_go02

Unless you're talking about the new diverging diamond interchange, which I think are fantastic, the traditional diamond is pure crap expect for low volume situations.

I actually hadn't heard of these until now- looked it up on Google, wow, are they ever cool! Very clever design. The perfect solution for urban expressways where land is at a premium, the only problem would be that people are likely to be confused by the flow reversal and the odd merging pattern. Well, that and how would a truck carrying an oversize load (a digger, for example) be able to bypass a low bridge using these interchanges?

[haljackey]

Originally Posted by Wharn

I actually hadn't heard of these until now- looked it up on Google, wow, are they ever cool! Very clever design. The perfect solution for urban expressways where land is at a premium, the only problem would be that people are likely to be confused by the flow reversal and the odd merging pattern. Well, that and how would a truck carrying an oversize load (a digger, for example) be able to bypass a low bridge using these interchanges?

There's also the Single Point Diamond Interchange, or Single Point Urban Interchange (SPUI). They handle all left turn movements in a single signalized intersection.

I drove through this one in the Detroit suburbs a few days ago due to a closure on I-94 to the east and used this to get back on from a detour. Works well even with high volumes: http://goo.gl/maps/Fqz60

[eemy]

I think the issue with the single point diamond interchange is that the crossing structure needs to be larger to accommodate it.

[Yahoo]

Originally Posted by LeftCoaster

I always found BC roads to be in decent shape but underbuilt.

Maybe it's different outside of the lower mainland?

Yes, it's definitely different. Take a trip on the Trans Canada to the Alberta border. They've been slowly upgrading some of the awful parts for quite some time, but most of the highway is still sitting in its 1950's configuration. Even in the 50's it wasn't built to spec. It's actually quite embarassing for the province - rippling on the pavement and potholes everywhere in some sections (repaired this year after years of ignoring the road surface), but I'm happy to see they are pushing forward and have replaced some of the most dangerous bridges.

The biggest issue is the slow pace of construction. The road has been ignored for so long it'll take a couple hundred more years to twin it at the rate they're proceeding. I realize it's often rough terrain - but that's the case in much of Canada. Even the easy parts have been ignored for the most part. They're focusing on the most dangerous bridges which I agree with since narrow bridges with sharp turns and no shoulders at the bottom of steep hills are quite common.

The cool pictures you see of the bridges in BC don't show the scary bridges they replaced - or the dozens that remain.

[Yahoo]

In Alberta they're wrapping up the twinning of the TCH through Banff. Unfortunately pictures aren't posted on the Banff website - but it's a much better highway. Lots of animal over and underpasses, animal fencing, and wide divided highway with wide shoulders. The nicest highway in Alberta. (the ring roads around Calgary and Edmonton are pretty sweet too)

Unfortunately since it's in a national park the highway is built to 110 kph specs but the speed limit is stuck at 90. This just leads to a lot of speeding - even by police and construction workers. They should post a realistic speed limit (at least 100) since it would be safer for everyone. Hopefully there isn't some "written in stone" rule that highways in the national parks have to be 90 max. It's a main transportation corridor and full of animal protection measures so hopefully something can be done.

[Dado]

Originally Posted by go_leafs_go02

Find me one urban diamond interchange that works well from a capacity standard in peak period, as that involves 4 separate left turn movements, while a Parclo A4 involves only 2. Let's see how the Linc in Hamilton worked if all interchanges were diamonds.

Intersection capacity doesn't concern me; pedestrian and cyclist safety does. The A4 Parclo with its high speed diverge and merge lanes fails miserably on those grounds and therefore should not be considered at all. We've already ruled out full cloverleafs (which have theoretically higher capacity still) on safety grounds, so rule out A4 Parclos on the same grounds.

Besides, the diamond design is no worse capacity-wise than a standard arterial-arterial intersection which would be found along the rest of the arterial. Why the special concern for the ability of an intersection to push traffic onto a freeway?

Moreover, the interchanges that are the worst for cyclists are where traffic is all able to move quickly without having to come to stop, which are hardly the circumstances under which a diamond is likely to fail anyway. We could quite readily replace most Parclo A4s with diamonds without any real capacity issues showing up.

Unless you're talking about the new diverging diamond interchange, which I think are fantastic, the traditional diamond is pure crap expect for low volume situations.

Yes, the diverging diamond is a good design that can be made reasonably safe for cyclists and pedestrians so long as the arrangement for the right-turn onramp isn't designed for a high speed turn-off. If diamonds are unable to handle the load, then this would be a suitable replacement.

Here's a perfect example of what should be done for all sidewalks/bike lanes crossing over a loop ramp, make them cross at a 90 degree angle, and require them to yield to vehicles.

Isn't that getting your priorities reversed? Making straight-ahead travelling cyclists and pedestrians yield to cars turning onto a freeway?

I've riden through there, and the line of sign is fantastic, drivers will see you, slow down, and let you cross with no issues. Safety was not a risk in any way to me.

http://goo.gl/maps/Atu5H

Was this supposed to be an example of a *good* design?

Just look at the design there - it forces a virtually instantaneous 90° turn on the cyclist's part, while heading downhill no less. To the extent it is "safe" it is only so because the cyclist has to yield. In a sense it is requiring that which many cyclists probably end up doing at loop onramps anyway.

But in the southbound direction, even that's not true because no one has a clear right of way. The cyclist doesn't have a yield (either sign or road paint) and neither do the cars entering the loop ramp (which is a basic problem of all the onramps on most A4 Parclos). In Ontario, and I'm sure it is the same in BC, at an uncontrolled intersection - which is what that now is - the person to the right has the right of way. That means the cyclist has right of way. The phrase "right but dead" comes to mind.

Moreover, look how the merging from the offramps was dealt with on either side of the interchange: it wasn't.

It goes to show how truly little thought was put into it. The traffic engineers only looked at it from the perspective of a motorist entering or exiting the freeway and not from the perspective of a cyclist continuing straight ahead.

Overall, that interchange would have been a lot better as a B2 design with the 'other' side of the intersections either side of Hwy 99 leading into 40th Ave & Nicomekl Rd. Besides being a lot "neater" and safer, it would also mean a lot less out-of-the-way travel for those going along 40th and Nicomekl.

[Wharn]

Looks like people are thinking about tearing down the Gardiner once again. I love how instead of proposing the use of tolls to pay for repairs, certain councillors immediately default to the demolition option. They say the Gardiner's repairs costs are too high, but just conveniently ignore the fact that it would cost about $245 million more to rip it down than it would to completely overhaul it.

I've never really understood the logic behind this, because if you want to improve access to the lake, removing the highway will do absolutely nothing. It isn't even much of an obstacle right now, and you still have a 10-foot railway embankment to deal with. Not only that, but nobody has proposed any realistic replacement options- a 10-lane boulevard is not adequate (nor is it very pedestrian-friendly, IMO). You would need a lakeshore subway or some other set of rapid transit lines to fully replace this roadway.

http://news.nationalpost.com/2012/12/05/...itation-to-put-500-million-into-repairs/

[haljackey]

The only good replacement for the Gardiner is to put it underground like the Big Dig project in Boston. The problem is this would be so expensive that no level of government would ever want to pay for it.

If it ever gets built one day I'd also like to see a subway line built down there while they're at it. Adding tolls until it's paid for (like the Coquihalla Highway) would be ok as long as the fees were low, not like 407 pricing.

Either that or keep maintaining/refurbishing the thing. Toronto doesn't have enough alternative routes like other cities of it's size so the Gardiner must be spared from demolition.

[niwell]

Originally Posted by Wharn

I've never really understood the logic behind this, because if you want to improve access to the lake, removing the highway will do absolutely nothing. It isn't even much of an obstacle right now, and you still have a 10-foot railway embankment to deal with. Not only that, but nobody has proposed any realistic replacement options- a 10-lane boulevard is not adequate (nor is it very pedestrian-friendly, IMO). You would need a lakeshore subway or some other set of rapid transit lines to fully replace this roadway.

I've always maintained that the biggest barrier to the lake and areas south of the Gardiner is actually Lakeshore Blvd. It's completely inhospitable and dangerous/annoying to cross at the best of times. If there was a serious move to improve connectivity I would like to see Lakeshore reduced significantly with a rework of entry/exit lanes to the Gardiner in some manner. Where possible structures could be built underneath the Gardiner (as has been done in other cities with elevated expressways) or in some cases park space similar to what has been done further east at underpass park.

After doing a quick search I see that spacing has (unsurprisingly) written about this already: http://spacingtoronto.ca/2007/08/05/what-to-do-with-the-gardiner-expressway/


In any event the Gardiner is too important of a commercial artery to remove completely and too expensive to tear down. In a perfect world tunneling may be the best option but that isn't happening anytime soon.

[sonysnob]

Some additional photos, taken today. As is illustrated in the photos, the future westbound express lanes are mostly paved.









More and larger:
http://www.asphaltplanet.ca/ON/hwy_401_images/Hwy401_HurontarioCons_images.htm#Dec12

[FrAnKs]

Ontario's kicking asses ! Love it.

Is it Misssisisausssaga's Skyline up in the right corner?

[Techman224]

Originally Posted by FrAnKs

Ontario's kicking asses ! Love it.

Is it Misssisisausssaga's Skyline up in the right corner?

Doesn't look like it, Downtown Mississauga is due south. The photo is pointing east, so that would be part of Downtown Toronto.

[LeftCoaster]

Looks like Yonge/Eglinton skyline to me.

[The_Architect]

Originally Posted by niwell

I've always maintained that the biggest barrier to the lake and areas south of the Gardiner is actually Lakeshore Blvd. It's completely inhospitable and dangerous/annoying to cross at the best of times. If there was a serious move to improve connectivity I would like to see Lakeshore reduced significantly with a rework of entry/exit lanes to the Gardiner in some manner. Where possible structures could be built underneath the Gardiner (as has been done in other cities with elevated expressways) or in some cases park space similar to what has been done further east at underpass park.

After doing a quick search I see that spacing has (unsurprisingly) written about this already: http://spacingtoronto.ca/2007/08/05/what-to-do-with-the-gardiner-expressway/

In any event the Gardiner is too important of a commercial artery to remove completely and too expensive to tear down. In a perfect world tunneling may be the best option but that isn't happening anytime soon.

This is my perfect-world-unlimited-funding-no-stupid-politics vision for the situation...

1. The Gardiner, though great infrastructure and civil engineering at the time, is decrepit and an eyesore now, with maintenance costs rising and annoyance at the grim dark underbelly becoming more prominent. Tear it down (wait for it...)

2. Bury the Gardiner, a la Big Dig (see why this is the perfect world scenario), having the underground portion only between Strachan and Cherry (it could be Bathurst and Sherbourne though, I'd prefer having Fort York less isolated). This already opens up the waterfront to a good chunk of the downtown both physically and mentally.

3. Lakeshore. I agree with you, Lakeshore as it is in downtown now is terrible, ugly and dangerous. It is necessary, however, so maybe either keep it the same size or reduce it by a lane each way, and put a median in the middle (something bigger than the basic median, something with vegetation in the middle). Make it more attractive, give a space for pedestrians to stop if they don't make it all the way across, and make it seem less dangerous. Look at Chicago, despite them beautifying up their waterfront, they have their own giant, dangerous Lake Shore Drive cutting it off. Medians do a hell of a lot.

Now, you still have the tracks to deal with, which I think is a huge barrier in itself, but in those 3 (very expensive in reality) steps you take care of 2 huge physical and mental barriers that cut off Toronto's downtown from the beautiful natural setting it was given .

tl;dr Gardiner sucks, bury it, median up Lakeshore, love life.

[sa230e]

Originally Posted by The_Architect

This is my perfect-world-unlimited-funding-no-stupid-politics vision for the situation...

1. The Gardiner, though great infrastructure and civil engineering at the time, is decrepit and an eyesore now, with maintenance costs rising and annoyance at the grim dark underbelly becoming more prominent. Tear it down (wait for it...)

2. Bury the Gardiner, a la Big Dig (see why this is the perfect world scenario), having the underground portion only between Strachan and Cherry (it could be Bathurst and Sherbourne though, I'd prefer having Fort York less isolated). This already opens up the waterfront to a good chunk of the downtown both physically and mentally.

3. Lakeshore. I agree with you, Lakeshore as it is in downtown now is terrible, ugly and dangerous. It is necessary, however, so maybe either keep it the same size or reduce it by a lane each way, and put a median in the middle (something bigger than the basic median, something with vegetation in the middle). Make it more attractive, give a space for pedestrians to stop if they don't make it all the way across, and make it seem less dangerous. Look at Chicago, despite them beautifying up their waterfront, they have their own giant, dangerous Lake Shore Drive cutting it off. Medians do a hell of a lot.

Now, you still have the tracks to deal with, which I think is a huge barrier in itself, but in those 3 (very expensive in reality) steps you take care of 2 huge physical and mental barriers that cut off Toronto's downtown from the beautiful natural setting it was given .

tl;dr Gardiner sucks, bury it, median up Lakeshore, love life.

Beauty is a subjective thing. I love the Gardiner. I think elevated freeways are awesome, something to be proud of not buried. It's like driving through the sky between the buildings. It's like the Jetsons.

I don't think they look bad on the ground either. It's just a long bridge sitting on concrete piers, a piece of utilitarian urban architecture. I don't get why that's so unsightly. It's not a garbage dump. And besides it's getting so boxed in by condos that you see less and less of it from the surrounding streets by the year.

[Wharn]

Originally Posted by The_Architect

This is my perfect-world-unlimited-funding-no-stupid-politics vision for the situation...

1. The Gardiner, though great infrastructure and civil engineering at the time, is decrepit and an eyesore now, with maintenance costs rising and annoyance at the grim dark underbelly becoming more prominent. Tear it down (wait for it...)

Part of the reason why maintenance costs continue to rise is because they city keeps under-spending on the budgeted amounts:

http://news.nationalpost.com/2012/12/06/gardiner-expressway-repairs/

We'd need to get an auditor to look at this, but $40M is a mighty large maintenance gap. By failing to allocate repair costs properly, the problem got exponentially larger as the years went on. I also agree with sa230e, beauty is in the eye of the beholder. Personally I don't really have much of an opinion on the appearance of the Gardiner, but I can definitely say it looks about 100 times better than the Autoroute Métropolitaine in Montreal. Going underneath that, you're exposed to a never-ending crapfest of rust, decay and atrocious patchwork. The Gardiner looks just fine in comparison; throw on a few LEDs and maybe some creeping charlie-ish plants and it'll look perfectly presentable.

Originally Posted by The_Architect

2. Bury the Gardiner, a la Big Dig (see why this is the perfect world scenario), having the underground portion only between Strachan and Cherry (it could be Bathurst and Sherbourne though, I'd prefer having Fort York less isolated). This already opens up the waterfront to a good chunk of the downtown both physically and mentally.

I like this idea but it would be outrageously expensive, and I'm sure about 30 years down the road you'll have the same maintenance issues since you're essentially going to be tunneling through landfill, not bedrock. And either way, most of the land between the lake and the Gardiner is owned by developers, so the only people who would really benefit from such an endeavour would be the folks in the condos. I'd much rather see the money spent on more subway lines.