Quote:
Originally Posted by supafamous
It's provisioned, as needed, to be expanded to 6 lanes down the road but, as roastpuff mentioned, New West objected to 6 lanes because they don't have road capacity for that much traffic.
Traffic volume forecasting is notoriously inaccurate - traffic engineers over the years have grossly exaggerated how much traffic volumes will grow. Even if there was demand for the volume they forecast there's no viable land available for new roads to be built (especially considering how much land is worth). We already spend something like 25-35% of land on roads and parking - it's just not practical to keep adding lanes as they don't carry enough people.
In relation to this, DH had some useful data on traffic volume of bridges:
https://dailyhive.com/vancouver/iron...raffic-volumes
Reading between the lines a few things show up:
- The max capacity of a lane is around 20-22k vehicles per day. The Second Narrows and the Massey are pretty darn congested at that volume. The Lions Gate at 19k/day is merely "quite busy".
- You can squeeze more capacity out if the lanes are standard size like the Port Mann. If the Second Narrows had standard lanes it could probably handle 24-25k vehicles a lane (ignoring capacity on both ends of the bridge)
- The old Patullo was only handling about 15k vehicles per day. This is probably because the narrow lanes and various closures made 15k the max compared to other bridges.
- The new Patullo/Riverview with its standard sized lanes should give the bridge about 33-50% more capacity than before even though it's the same number of lanes. They didn't need to add 2 more lanes to make traffic better - if they did 6 lanes right off the bat they'd be looking at a doubling of capacity compared to the old bridge so I get why New West said "Hell no" to that. |
To add, the congestion issues on New West side stemmed from McBride further North at 6th and 8th Ave backing up down to the Bridge (which a new bridge can't fix), all the people/trucks exiting the Pattulo to loop down to Columbia and getting stopped at 2 lights, and then the people/trucks from Columbia trying to take the on-ramp onto the Pattulo, which was impossible to merge onto in the past because they had to sit at a yield sign and wait for traffic to clear before they could go.
The new bridge/design improves on 2 of these major issues, because there's an off-ramp directly from the bridge onto Columbia, bypassing two lights, and there will be a new on-ramp from Columbia onto the bridge that has it's own dedicated lane, so they won't have to sit and wait.
Eventually, they'll have the off-ramp on the Surrey side that ties directly into Highway 17 too.
Even at 4 lanes, the new bridge is significantly more efficient. People think 6 is better than 4, therefore it sucks, but they don't actually think about where the source of the congestion is. We'll need to wait for all the on/off ramps to be finished first this year, but if the traffic still ends up being backed up from Mcbride or the new Columbia off-ramp onto the bridge, then you know the bridge isn't the problem. You could build 10 lanes and it'd still be backed up.