Highways in Canada

[sa230e]

Originally Posted by Symz

Does anyone who knows more about construction and highways know what it is they could be doing with these foam blocks for the WE Parkway? I can't figure it out.

http://blogs.windsorstar.com/2012/08/31/windsor-essex-parkway-one-year-later/

Commuters through the site probably noticed a few weeks ago workers were burying what appeared to be giant Styrofoam blocks in the roadbed.

“It’s not Styrofoam,” Hatchell says. “It’s ‘light-weight fill.’” The blocks, made of a structured polystyrene, are commonly used in areas of soft subsoils where the added weight of deep crushed stone could eventually destabilize the subsurface. The consortium doesn’t want to have to replace asphalt or concrete surfaces sooner than necessary. The blocks, which are only pressure-fitted together, are also cheaper than stone fill.

[tradephoric]

Does anyone know why Parclo A4 interchanges are so popular in Ontario as opposed to the Parclo B4? There seems to be some definite advantages to using the B4 type but maybe I'm missing something. Any thoughts or input on this?

[go_leafs_go02]

Originally Posted by tradephoric

Does anyone know why Parclo A4 interchanges are so popular in Ontario as opposed to the Parclo B4? There seems to be some definite advantages to using the B4 type but maybe I'm missing something. Any thoughts or input on this?

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

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.

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.

[haljackey]

Pedia Wiki:
http://en.wikipedia.org/wiki/Parclo

There's sections dedicated to the B4 and A4 designs so you can spot the differences.

Then there's newer A4 designs that have both on-ramps merge before merging onto the highway itself. This makes one entry point opposed to two, and generally have a longer acceleration lane (room to merge).

Example I made in SimCity 4:

Standard A4:


A4 with single entry points:


There you have it

[tradephoric]

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

That’s a very legitimate point. Here’s an example of a Parclo B4 interchange in Troy, Michigan where an indecisive driver who exits the freeway at the last possible moment has only 100 feet to decelerate before encountering the loop ramp:

I-75 & 14 Mile in Troy, Michigan


Ramp designs that increase the deceleration lengths should reduce the potential for run-off accidents. Here are a few good examples:

M-59 & Squirrel Rd. in Rochester Hills, Michigan

The off-ramp shaded in blue slowly diverges from the main freeway traffic (green shaded area) providing drivers adequate distance to decelerate.

I-80 & S. Dewey St. in North Platte, Nebraska

An example of a Parclo B4 interchange with a single exit point (same idea as haljackey’s SimCity example).

[davidivivid]

Autoroute Robert-Bourassa (A-740)


300 m par Patrick Matte, sur Flickr

[sonysnob]

Originally Posted by davidivivid

Autoroute Robert-Bourassa (A-740)


300 m par Patrick Matte, sur Flickr

Great photo!

[FrAnKs]

Nice ! I take this highway everydays !

[haljackey]

Is that an entrance and exit ramp on the right of that photo? Talk about a short weave area!

[PhilippeMtl]

Originally Posted by haljackey

Is that an entrance and exit ramp on the right of that photo? Talk about a short weave area!

The worst I have seen is in Turcot Interchange in Montreal.

https://maps.google.ca/maps?hl=fr&ll=45....aw8DzNAo7k59zpvM6w&cbp=12,22.93,,0,17.82

[sonysnob]

Originally Posted by haljackey

Is that an entrance and exit ramp on the right of that photo? Talk about a short weave area!

Not to mention the pedestrian walking down the freeway's sidewalk on the left side of the photo.

[vegeta_skyline]

Highways in Quebec are a little different than the norm I see.

[Dmajackson]

^Every province has widely different highways thats for sure

Just this summer I've been in three different provinces and the changes are amazing. For urban set-up Alberta wins (overall better nothing specific), for rural set-up NB wins especially with its forested medians (no night-time glare!), and for interchanges NS wins (roundabouts and long merges).

[le calmar]

Originally Posted by sonysnob

Not to mention the pedestrian walking down the freeway's sidewalk on the left side of the photo.

I've never seen a sidewalk on a freeway in Quebec before. This is probably an isolated case.

[go_leafs_go02]

Originally Posted by Dmajackson

^Every province has widely different highways thats for sure

Just this summer I've been in three different provinces and the changes are amazing. For urban set-up Alberta wins (overall better nothing specific), for rural set-up NB wins especially with its forested medians (no night-time glare!), and for interchanges NS wins (roundabouts and long merges).

Tis true.

USA interstates are so very similar from state to state, while in Canada you go from Ontario ultra-modern freeways to Quebec's horribly maintained, poorly designed freeways and interchanges.

[Smevo]

Videos of parts of highways in Cape Breton. Two are "freeway" (the TCH and Hwy 125), the other is a trunk (Cabot Trail). Cross posted from the Atlantic Highways thread.

Sorry for the bluriness in some of the videos. And I selected the tunes at random, so if you don't like them just hit mute (one of the videos was flagged for a song on the radio, so rather than risk it being taken down, I just selected the YouTube tunes instead).

All videos by myself taken by propping the camera under the passenger headrest and remotely starting and stopping recording. These were all taken on a Tuesday evening.

South side of Cape Smokey on the Cabot Trail. Taken around 5pm.
• Video Link

Kelly's Mountain hairpin on the TCH (sorry for the bluriness, the camera autofocused on something it shouldn't have) Taken around 6pm
• Video Link

Highway 125 twinning section from Sydney River to Grand Lake Rd. Taken around 7pm.
• Video Link

[tradephoric]

A major disadvantage of the parclo A4 interchange is that it leads to poor traffic signal progression along the arterial. The traffic signals controlling the on/off ramps at an A4 interchange stops both directions of travel. Here is an example of a Parclo A4 interchange at HWY 410 & Steeles Avenue in suburban Toronto (the red icons irepresent traffic signals that stop both directions of travel):



Parclo A4 interchange time-distance diagram


The time-distance diagram above illustrates how an A4 interchange can ruin 2-way progression. While it it possible to achieve good signal progression for EB Steeles traffic, it leads to green-red progression for WB Steeles traffic. Toronto seems to have a rigid 2km x 2km road network (at least in the burbs) making good traffic signal progression possible. However, the potential for good traffic signal progression is greatly diminished due to the large number of A4 interchanges that dot the city.

Widespread use of Parclo A4 interchanges in Toronto = poor traffic signal progression


Parclo B4 interchanges (partial cloverleaf w/exiting loop ramps) would greatly improve traffic signal progression along Toronto arterials since any traffic signal controlling the on/off ramps stop only one direction of travel. Here is a time-distance diagram of the same arterial when a Parclo B4 interchange is selected:

Parclo B4 interchange time-distance diagram


NOTE: Diverging Diamond Interchanges (DDI) and Single Point Urban Interchanges (SPUI's) are also plagued by poor traffic signal progression along the arterial.

[davidivivid]

300 m par Patrick Matte, sur Flickr

Originally Posted by haljackey

Is that an entrance and exit ramp on the right of that photo? Talk about a short weave area!

Originally Posted by le calmar

I've never seen a sidewalk on a freeway in Quebec before. This is probably an isolated case.

Well, this is indeed an isolated case: this picture was taken at the beginning of the highway, in the middle of the city right next to Laval University campus. At that particular location, it is more an urban boulevard with a 70 km/h speed limit than a true highway. That being said, the specific entrance and exit ramp you are refering to is being completely redesigned as we speak. Honestly, driving in Quebec City is a breeze.

[Airboy]

Just finished a drive along the old highway 1route in the Fraser Cayon. I forgot how fun the drive was. Even with the slow trucks. And the drive along the Yellow head is great now without the tourist traffic. But the drive into downtown Vancouver sucks.

[leftimage]

Here's a dashcam time lapse I did while driving from Montreal to roughly Kingston, Ontario. 3 and a half hours compressed to 90 seconds. Enjoy.

• Video Link