Highway 17 (SFPR) Upgrades

[c041v]

Fair points, but the rule book is pretty clear;

DESIGN-BUILD AGREEMENT
Schedule 4: DESIGN AND CONSTRUCTION
Part 2: Design & Construction Requirement
ARTICLE 1 LANING AND GEOMETRICS DESIGN CRITERIA
1.2.3 Interchanges
(d) The use of left side exit and entrance ramps shall not be permitted.

http://www.partnershipsbc.ca/wp/wp-c...t-Redacted.pdf

edit: The Queensborough wye dates back nearly 60 years, a lot has changed since then. The 91 SB exit off Knight street is not a true left hand exit, it is a two lane right hand exit that then wyes off after. Again, something from a different era.

[Dengler Avenue]

I wonder if it can be relaxed given environmental constraints.

[officedweller]

I looked at that trumpet design more closely - yeah, it really is a left exit.

[Mininari]

Originally Posted by officedweller

I looked at that trumpet design more closely - yeah, it really is a left exit.

Well there's an easy 'hack' to make it not a left-exit.

Just sign / stripe the Eastbound-to-Northbound left turn movement as the PRIMARY movement, and make the split to Nordel Way the 'exit' -- it would thus be a right-hand exit, and not 'merge' with the 91 exit traffic if each of the 'exit-to-Nordel-Way-EB' traffic movements had its own dedicated lane up the hill.

Does this make sense?

[waves]

Originally Posted by Mininari

Well there's an easy 'hack' to make it not a left-exit.

Just sign / stripe the Eastbound-to-Northbound left turn movement as the PRIMARY movement, and make the split to Nordel Way the 'exit' -- it would thus be a right-hand exit, and not 'merge' with the 91 exit traffic if each of the 'exit-to-Nordel-Way-EB' traffic movements had its own dedicated lane up the hill.

Does this make sense?

This is clever.

I imagine however that the primary movement is defined by the movement that has the highest volume and you can't simply pick it - If the numbers are close, or, are potentially inhibited by the current design (latent demand) then you may be able to make the argument that future expected movements should dictate the design. Does someone have the volume movements for the interchange and can share those numbers?

To speculate, just looking at the design proposed by the province for the green movement however, the through volume has two-intersections and the northbound on-ramp only has one. That might indicate to me that the primary movement is the northbound on-ramp. However, it is difficult to decipher intention from unintended consequence without the volume counts.

[aberdeen5698]

Originally Posted by waves

I imagine however that the primary movement is defined by the movement that has the highest volume and you can't simply pick it..

I'd expect the primary movement to be the one where you don't end up on a different highway. You "exit" the highway you're on to reach a different route.

[officedweller]

Agreed.
That's a Garden City Way @ Granville Ave. type of solution... which can be confusing to people.

[zahav]

Garden City and Granville is the most bizaare intersection in the LM, arguably. Anyone who hasn't gone either NB on Garden City or Westbound on Granville must try it lol

[VancouverOfTheFuture]

Originally Posted by zahav

Garden City and Granville is the most bizaare intersection in the LM, arguably. Anyone who hasn't gone either NB on Garden City or Westbound on Granville must try it lol

a remnant of the old interurban days. it used to run down that median. i like it because its funky/convoluted; its unique.

[flipper316]

They were doing some digging tonight southeast of the intersection and some of the lanes were blocked off.

[gkz]

Overall the latest design is innovative and a good improvement over the original! I think there may be some room for some practical improvements however, without going full double trumpet.

Originally Posted by waves

AFB Double Trumpet:

People are focusing on the green movement, but let's instead look at the red one - Nordel Way to 91 SB. We can eliminate this light.

Current plan in more detail:

Originally Posted by c041v

The left hand exits for Nordel EB to Hwy 91 NB and Nordel WB to Hwy 91 SB are a non-starter from a geometric perspective. Obviously a lot of other options open up elsewhere were this condition allowed.

For the existing plan, Nordel Way to 91 SB is already a left hand exit! It's exiting to a light, but still, it's a left hand exit.

Originally Posted by c041v

The proposed Nordel Way Way to Hwy 91 SB laning is conveniently wedged between what is a very tight area. Interchange ramp lane widths vary between 3.7-4.8 m for tracking, which just won't fit in this space. You are also dropping a WB lane immediately after crossing the structure, which means you only have one Nordel Way WB through lane, which is less than the current design in terms of capacity. Sure, you could widen the existing structure to 5 lanes, but this comes with a huge cost increase as the existing structure is not being replaced with this design.

We can make room: without the light, there is no longer a need for the barrier to separate 91C to 91 SB traffic from the light, saving room. That entire new roadway can be adjusted slightly more south. Unlike 91C to 91 NB, there is no existing bridge we need to modify and impact existing traffic - this is all new roadway and bridge.

The current design with the light does not use a full lane on the bridge to the exit. So in comparison to the current design, this can stay the same - the exit starts after the bridge.

My terrible drawing:

[Marshal]

It is too bad we do not have access to the full design and decision making process. Knowing engineers as well as I do tells me that at some point early on, before money numbers were introduced, someone printed off a simplified drawing of every possible routing option (as in dozens). I would love to see the record of the distillation of options as other requirements were brought into the work: how did they get to their outcome and why.

[Metro-One]

Originally Posted by Marshal

It is too bad we do not have access to the full design and decision making process. Knowing engineers as well as I do tells me that at some point early on, before money numbers were introduced, someone printed off a simplified drawing of every possible routing option (as in dozens). I would love to see the record of the distillation of options as other requirements were brought into the work: how did they get to their outcome and why.

As am I, and I did actually get a response from them regarding my suggestion of using the double trumpet.

They said that they have looked at many designs and have come to the conclusion they have selected because it meets all the expectations of the project.

What caught my eye though was they directly stated that this design requires minimal structures as of that was a good thing.

For me that aspect translates to penny pinching / value engineering.

Don’t get me wrong, overall I think this is a good project, but like so many other highway projects in BC with just a little more ambition it could have reached that next level (in this case full free flow would have elevated it to a Cape Horn level interchange)

[officedweller]

There's also a redundant westbound Nordel to northbound 91 route.
Would that ever be useful?

[aberdeen5698]

Originally Posted by Metro-One

...What caught my eye though was they directly stated that this design requires minimal structures as of that was a good thing.

For me that aspect translates to penny pinching / value engineering...

Projects of all types will almost always come in somewhere between the bare bones minimum and the excessively gold-plated over-engineered solution. And whenever you're in that middle ground, you're going to get criticized from both ends. My rule of thumb is that if you're being criticized equally by people who think you've spent too much and people who think you've spent too little, then you've probably done pretty well.

[libtard]

Originally Posted by aberdeen5698

Projects of all types will almost always come in somewhere between the bare bones minimum and the excessively gold-plated over-engineered solution. And whenever you're in that middle ground, you're going to get criticized from both ends. My rule of thumb is that if you're being criticized equally by people who think you've spent too much and people who think you've spent too little, then you've probably done pretty well.

No one thinks they spent too much and everyone thinks they spent too little though. You heard metro one’s response he got from the MoT. This design allows them to use the least amount of structures. They should make the whole thing an at grade signalized intersection, that would require even less structures!

[Marshal]

Originally Posted by Metro-One

They said that they have looked at many designs and have come to the conclusion they have selected because it meets all the expectations of the project.

This is an insulting response on their part. We (the public) are grown up enough to receive real concrete rationals for design choices and other issues.

Originally Posted by Metro-One

What caught my eye though was they directly stated that this design requires minimal structures as of that was a good thing.

This is better, but still way too general to be truly informative.

[makr3trkr]

This has to be the worst bit.

I guarantee there will be accidents here because trucks won't want to yield / come to a stop before going uphill.

[c041v]

Originally Posted by Marshal

It is too bad we do not have access to the full design and decision making process. Knowing engineers as well as I do tells me that at some point early on, before money numbers were introduced, someone printed off a simplified drawing of every possible routing option (as in dozens). I would love to see the record of the distillation of options as other requirements were brought into the work: how did they get to their outcome and why.

They would have have cost much, much more.

The convenient dismissal of budgets has me chuckling about how some here could have surely done better if put in the same circumstances. Anything is possible with no rules and and unlimited resources. I have been unfortunate to see a project that features either.

Originally Posted by aberdeen5698

Projects of all types will almost always come in somewhere between the bare bones minimum and the excessively gold-plated over-engineered solution. And whenever you're in that middle ground, you're going to get criticized from both ends. My rule of thumb is that if you're being criticized equally by people who think you've spent too much and people who think you've spent too little, then you've probably done pretty well.

This is a good take. It is impossible to satisfy every stakeholder, as their interests are often at odds. The requirements and standards are set to ensure consistency across the region, and Province. There's countless reports and studies for these types of projects that determine, through statistical analysis, what the major issues are.

91/17 does not justify the Cape Horn treatment as the traffic volumes are substantially lower on all movements. Best practice is to design and build for the needs of many, present and future - not overbuilding all movements because traffic lights are inconvenient to the few.

[c041v]

Originally Posted by gkz

Overall the latest design is innovative and a good improvement over the original! I think there may be some room for some practical improvements however, without going full double trumpet.



People are focusing on the green movement, but let's instead look at the red one - Nordel Way to 91 SB. We can eliminate this light.

Current plan in more detail:




For the existing plan, Nordel Way to 91 SB is already a left hand exit! It's exiting to a light, but still, it's a left hand exit.



We can make room: without the light, there is no longer a need for the barrier to separate 91C to 91 SB traffic from the light, saving room. That entire new roadway can be adjusted slightly more south. Unlike 91C to 91 NB, there is no existing bridge we need to modify and impact existing traffic - this is all new roadway and bridge.

The current design with the light does not use a full lane on the bridge to the exit. So in comparison to the current design, this can stay the same - the exit starts after the bridge.

My terrible drawing:

I'll keep it short and sweet: The vertical curve leading to the west abutment of the the proposed new structure is already maxed out. Your proposal requires what appears to be an additional structure and would require the profile of Nordel Way EB to be lifted some 50+m to the west, which would require additional walls, ground improvements and embankment, all on top of the existing Highway 91C EB to to Highway 91 SB off-ramp.

All for a movement that sees a few lost souls who live somewhere north of 72nd Ave that are trying to get South Surrey. Seems... excessive.