New roundabout on Canadian motorway

[Truvelo]

Just when you thought the UK was bad enough with putting at-grade roundabouts with nasty deflection on high quality GSJ'd dual carriageways I came across this in Canada. Having did a bit of research the roundabout was 10% of the cost of a GSJ but why bugger up a perfectly decent route which acts a diversion if the Trans Canada just the south is closed. I've also discovered plans to destroy the freeflowing GSJ just the east where it joins Route 7. This will also see a roundabout plonked on the mainline

https://www.google.co.uk/maps/@45.94134 ... 704516,17z

[KeithW]

Just when you thought the UK was bad enough with putting at-grade roundabouts with nasty deflection on high quality GSJ'd dual carriageways I came across this in Canada. Having did a bit of research the roundabout was 10% of the cost of a GSJ but why bugger up a perfectly decent route which acts a diversion if the Trans Canada just the south is closed. I've also discovered plans to destroy the freeflowing GSJ just the east where it joins Route 7. This will also see a roundabout plonked on the mainline

https://www.google.co.uk/maps/@45.94134 ... 704516,17z

Its stretching it a bit to call it a Motorway. This is actually a Provincial Route (New Brunswick Route 8.) The Trans Canada Highway is 1 km south of here and that carries most of the through traffic. Where the roundabout is there used to be a GSJ but it had on/off ramps for westbound traffic only and there was no access south towards Bishop Drive. This became a problem when business developed either side of the road. The problem with putting in a full GSJ seems to have been there wasn't enough space to shoehorn it in to the location. Since there was also no pedestrian access to the south it was considered by the city that a roundabout would allow the extra vehicular AND pedestrian access. The roundabout would serve to slow traffic down enough to make it reasonably safe. North of Frederiction NB-8 drops to an S2.

Its rather more like a UK Urban D2 than the M1 . New Brunswick has a total population that is rather smaller than Leeds and has more than 6 times the area of the whole county of Yorkshire. This road has more in common with the A421 at Milton Keynes than the M1

The TransCanada highway itself has some very iffy sections like this one in BC
https://www.google.co.uk/maps/@51.39888 ... 312!8i6656

Turning into or out of Field itself could be very iffy as the speed limit on that section was viewed more as a challenge than a restriction. Apart from the high speed traffic and at grade junctions you had to look at for Elk and mountain goats too.

[jackal]

It seems the roundabout was installed in 2014/15. Prior to that there was a LILO at the site of the roundabout on the westbound carriageway. I can see no evidence that there was ever a GSJ at this site, although I suppose it's possible before 2004 (the date of the earliest Google Earth imagery).

As for why the roundabout was installed, cost, space, NMU access and safety (the old westbound LILO was very tight and connected with a two-way single carriageway ramp) may all have played a role.

Without demolition it isn't easy to see how a full GSJ could have been fitted in even if you utilize the eastbound LILO to the east. The best I can come up with is a bridge at the site of the roundabout, with the westbound LILO here. The weaving distance would be 500m, which is not ideal but better than some existing sections on this road.

[WHBM]

The TransCanada highway itself has some very iffy sections like this one in BC

Having driven the length of the TCH (who else here has ?), well over half of it (total length 5,000 miles) is S2, and there are numerous sections where things are very sparse - in Northern Ontario there are still signs warning of substantial distances to the next fuel station. Everything seems to move at 60-70mph, and sight lines are invariably excellent. Field BC is a long way from any urbanisation.

[M19]

Just when you thought the UK was bad enough with putting at-grade roundabouts with nasty deflection

The entry angles are on a nice smooth tangent though, which will reduce the risk of entry path overlap - a pet hate of mine with modern roundabout designs in the UK.

[KeithW]

The TransCanada highway itself has some very iffy sections like this one in BC

Having driven the length of the TCH (who else here has ?), well over half of it (total length 5,000 miles) is S2, and there are numerous sections where things are very sparse - in Northern Ontario there are still signs warning of substantial distances to the next fuel station. Everything seems to move at 60-70mph, and sight lines are invariably excellent. Field BC is a long way from any urbanisation.

I havent driven the whole thing but have driven substantial parts.

Vancouver to Calgary in the west
Montreal to Winnipig on the eastern edge

The road is just such a set of contrasts. In Manitoba it was a wide D2 road with so little traffic it looked like of of those post end of the world movies at times. Getting in to Ontario it shrank down to a not very good S2 with a bad road surface and uncontrolled at grade junctions only reverting to D2 as you approach Sudbury

The section between Lake Louise and Golden felt very like the A9 between Perth and Blair Atholl with both roads following the same corridor as a major railway with view of mountains , lakes and river. Field only exists because the Candian Pacific Railway needed a place to water and coal its locos and house its workers. I stayed there for a few nights and the sound of the trains coming through at night was oddly soothing

[Truvelo]

I've driven it from Vancouver to Calgary and Fredericton to Truro. Fredericton was in 2006, long before the roundabout appeared.

Here are the proposals for the GSJ to the east of the new roundabout

http://i.imgur.com/SzP7H8y.png

[Bryn666]

It's a proven safer layout than presumably uncontrolled at grade turns at a daft angle.

If the traffic levels don't warrant free flow links you don't build them. Simple economics.

There's more to highway planning than ensuring someone can bomb through everything at 90 in a V8

[firefly]

It looks as if the local road authorities have come to reason. This roundabout is the first sensible junction along this otherwise over-engineered road. I guess, this road used to be the TCH, before it was by-passed and that the adjacent GSJ with its gigantic slip roads are a relic from a time when this road carried through traffic.

[jackal]

I've driven it from Vancouver to Calgary and Fredericton to Truro. Fredericton was in 2006, long before the roundabout appeared.

Here are the proposals for the GSJ to the east of the new roundabout

http://i.imgur.com/SzP7H8y.png

While they will retain one direction of grade separation, even that is in a direction in which the road immediately crashes into a large signalized junction

[James]

Just when you thought the UK was bad enough with putting at-grade roundabouts with nasty deflection

The entry angles are on a nice smooth tangent though, which will reduce the risk of entry path overlap - a pet hate of mine with modern roundabout designs in the UK.

Yes, looks much better than this type of garbage https://goo.gl/maps/1A9S2WR9iuF2 that finds its way onto our road network