Hennepin & Lyndale Bottleneck Project

[eluko]

Based on the photoshopped map above, I think there would be some sort of signalized control of flow into these roundabout points, sort of like Dupont Circle in DC.

I was thinking with the existing lights at the north and south ends it would provide enough traffic gaps to give every one a turn, but it wouldn't be a bad addition I suppose. They could always blink yellow during off-peak hours.

[mister.shoes]

I really like your idea, eluko, but I do have a concern: one of the benefits of a roundabout is that if a driver misses (or is blocked from taking) his exit, he just goes around again and takes it the next time. Your design has no such "escape hatch" for unlucky drivers. I think you'd have to complete the roundabout at each spot for it to be effective, even of those last bits get very little use.

[mulad]

I dunno -- A lot of roundabouts I've seen in MN and WI require you to be in the correct lane before you enter in order to be in the right spot to exit onto the road you want. Some can force cars to exit at certain points, like this one in Chippewa Falls which is offset enough to have 3 lanes on one side and just 1 on the other:

https://maps.google.com/maps?q=chippewa ... n&t=h&z=19

[eluko]

I dunno -- A lot of roundabouts I've seen in MN and WI require you to be in the correct lane before you enter in order to be in the right spot to exit onto the road you want. Some can force cars to exit at certain points, like this one in Chippewa Falls which is offset enough to have 3 lanes on one side and just 1 on the other:

https://maps.google.com/maps?q=chippewa ... n&t=h&z=19

I didn't really get too detailed on the lane configuration but the circles would have 3 lanes between entrance and exit points. Both the north and south circle only have one instance of this.
People driving north on Lyndale would be guided to the right and center lanes and people from 94 would be guided to the left and center lanes. The center lane would have the fork.
For northbound Hennepin the folks would have the left and center lane and southbound Lyndale would have the right and center lane. The center lane here would have the fork as well.

I understand roundabouts have had a tough time being built within the city proper lately, but I think once some of the planned ones do get built, seeing them get built here wont be such a shock.

[Nathan]

For a long time I was thinking about roundabouts for this area as well, and I could never quite wrap my mind around how everything could be put together, and then people started talking about diverging diamond intersections in other threads, and it really made a lot of sense and got me thinking about if that was possible with the Virginia Triangle. I made my own (not as pretty) version of the southern section trying this out. I haven't exactly thought through how to mesh Hen and Lyn back up, just haven't thought about it too hard yet... but I was thinking this could really create far easier and faster access to 94... I haven't thought out every intersection, but it seems fairly viable. Feel free to expand on, criticize and all that

Red is Northbound, Green is Southbound, with gold being the on/off ramps to 94, and blue being a new pedestrian/bike greenway that branches and bridges over to either side of the triangle.

[MNdible]

While there may be some radical reconfiguring of this area that could magically fix everything, I'm inclined to think that there are a lot of much more modest improvements that could make the area more humane without significantly cutting down on the north-south capacity for auto traffic.

I'd focus my efforts on really upgrading the two major east-west pedestrian crossings (Groveland and Oak Grove). I'd argue that there's nothing particularly bad about the north south pedestrian and bike routes through the area. I don't think that pedestrian bridges are the answer, because they tend to make an area feel more suburban, they are ugly, they take up a ton of space with mandatory ADA ramps, and people aren't going to want to walk up and down a couple of flights of stairs.

At Groveland, the biggest thing is fixing the terrible 4 southbound bus stop -- this should have been fixed 20 years ago. As part of this, that median could be improved and expanded.

[twincitizen]

One thing that has always bothered me about the bottleneck specifically is SB Hen/Lyn access to EB 94. NB Hen or Lyn to EB 94 is fairly harmless, except for the bicyclist-killing potential of Lyndale, but that's fixable, relatively inexpensively too.

SB Hen/Lyn traffic to EB 94 is simply in the bottleneck area for too long. There has to be a way to get those cars out of the bottleneck area and on the highway sooner (i.e. further north, i.e. in the tunnel not on top of it). Note to Uptownsport and other contrarians, this is not about bikes/transit vs. cars, but actually about cars vs. cars. Getting these cars on the highway sooner should improve traffic flow for all users. Is there a way to add an EB 94 entrance somewhere in the Dunwoody area? What about adding an access point along the EB 394 to EB 94 ramp back in that area? I realize this would probably require an additional eastbound lane in the tunnel, but it has been said that this would technically be possible.

[mattaudio]

My dream would be to rehab the Lowry Hill Tunnel for Lyndale/Hennepin through-traffic, then building new deep bore tunnels from 94/35W behind the Convention Center to 94/394 behind the Basilica. Then the current viaduct next to the Basilica could be softened or removed, and the 94 corridor from Lyndale to 3rd Ave could become a transit tunnel in the existing grade, then capped above grade with a reconnected street grid or a nice boulevard to move Wedge traffic eastward to relieve Franklin, 15th St, and Hennepin.

[MNdible]

SB Hen/Lyn traffic to EB 94 is simply in the bottleneck area for too long. There has to be a way to get those cars out of the bottleneck area and on the highway sooner (i.e. further north, i.e. in the tunnel not on top of it).

I like where your head is at on this, and I think were we able to do so, it would help quite a bit. I think the issue is that the tunnel is already grossly over capacity, and it's only workable to add this traffic and its necessary auxiliary lane after the tunnel, where there's the cross section for it.

[RailBaronYarr]

My dream would be to rehab the Lowry Hill Tunnel for Lyndale/Hennepin through-traffic, then building new deep bore tunnels from 94/35W behind the Convention Center to 94/394 behind the Basilica. Then the current viaduct next to the Basilica could be softened or removed, and the 94 corridor from Lyndale to 3rd Ave could become a transit tunnel in the existing grade, then capped above grade with a reconnected street grid or a nice boulevard to move Wedge traffic eastward to relieve Franklin, 15th St, and Hennepin.

I like this. Any serious thought on cost for a project like this??? What would this be relative to capping off 94 from Nicollet to Lyndale and reconnecting those grids to provide multiple routes N/S, while also limiting capacity at the triangle (and therefor Hennepin as a through-route)?

[eluko]

This idea of removing access to 94 from the triangle altogether isn't going to happen considering the whole idea of building 94 through this part of town was to provide access to these roads to begin with.

If we want to narrow the bottleneck from 9 to 4 lanes its not impossible, but the tunnel would need to be at least 10 lanes wide instead of 6 and that would require rebuilding the Walker. I like mattaudio's idea but a double decker slurry walled tunnel below the water table could cost into the billions.

If or when the Walker is rebuilt, then you would have the room to build tunnel on-ramps just south of Groveland from NB Lyndale, and just north of Oak Grove from SB Lyndale into the tunnel. This would eliminate the need for the extra lanes through the bottleneck.

[woofner]

This idea of removing access to 94 from the triangle altogether isn't going to happen considering the whole idea of building 94 through this part of town was to provide access to these roads to begin with.

This is not true - a number of routes for 94 were considered, some of which veered quite far from this particular location. This route was chosen due to the relatively few structures and amount of parkland needed to be acquired.

SB Hen/Lyn traffic to EB 94 is simply in the bottleneck area for too long. There has to be a way to get those cars out of the bottleneck area and on the highway sooner (i.e. further north, i.e. in the tunnel not on top of it).

This is a really great observation that has potential to change the whole bottleneck conversation. I'd think Glenwood would have enough capacity to handle at least half of this traffic - why not require the SB94 traffic exiting to Lyndale/Hennepin to do so north of Glenwood, then squeeze the Glenwood exit to EB 94 under the ramp from SB 94 to WB 394 (this may require reconstructing it to gain elevation sooner)? I don't think this would even require another lane in the tunnel if done in conjunction with adding another EB 94 exit east of the tunnel, and I think there were some ideas for that in MnDOT's downtown freeway study, somewhere around 3rd maybe?

A couple other thoughts about the Bottleneck: there is apparently a bit more money coming from the City, as the CLIC lists a $10.8m project budget with $5.3m coming from the Feds. The CLIC appears to allocate $3.85m from City sources (net debt bonds, special assessments, and stormwater revenue), and lists one other source (Municipal State Aid) that may be included in the TIP funding. If the TIP funded more than the CLIC anticipated and that overage is used to increase the scope rather than merely reduce the City's contribution, we could see a overall project budget of $14.5m.

That seems about right for reconstructing Hennepin and Lyndale between Dunwoody & Franklin, but obviously doesn't include the overpasses. In my opinion these are the worst part of the Bottleneck, since they do the most to make the facility feel more like a freeway than a street, making pedestrians uncomfortable and encouraging motorists to speed. They received some kind of renovation in 1987 and MnDot judges them to be in good shape even though they are brethren to the fallen 35W bridge, so I doubt we'll be rid of them any time soon. Still, I hope that any redesign of the Bottleneck makes the assumption that they will be removed, or at least the discussion considers that possibility. Other commenters are absolutely right that there are very few possibilities for getting between Downtown & Uptown, which is why it's crucial that one of the few routes be functional for all users.

Right now it is not. Minneapolis has proven itself incapable of keeping the sidewalk on Lyndale usable in the winter, and even if they did, the section under the overpasses would be as trash-strewn and sketchy as it is during the summer. It is completely unacceptable that the bike path and the sidewalk are shared between Groveland and Oak Grove. The sidewalk on Hennepin between Groveland and Douglas has a multitude of hazards coming from all directions. The sidewalk on Hennepin south of Douglas is unnecessarily narrow.

The city has a policy of prioritizing biking, walking and transit and encouraging mode shift to these modes. There is an enormous amount of space to work with in the Bottleneck - it's around 150' wide at its narrowest point, close to 300' wide at its widest, and the interchange area comprises about 9 acres of prime urban land - so I think it's possible to come up with a configuration that minimizes the impact on cars while greatly improving conditions for the other modes. But frankly, if not, City policy requires that cars get the cut. Sorry, drivers, now you know what life was like for the rest of us for the last 60 years (or at least you would if this policy were ever followed).

[eluko]

This is not true - a number of routes for 94 were considered, some of which veered quite far from this particular location. This route was chosen due to the relatively few structures and amount of parkland needed to be acquired.

Few structures? This was one of the most densely populated neighborhoods in the city before the highway came through. Do you know where I can find more info on this?

[Nick]

[eluko]

I see your point Nick, but I was referring to the buildings east of there.

[Nick]

You can zoom in/out and move around on the map if you're viewing it from a computer. Super cool website to spend half an hour on for no particular reason.

[UptownSport]

too bad more couldn't be elevated- Obviously the flyovers are getting up there already-
That'd leave space for more Green and perhaps subway / local traffic / trolley below.

Overall, it's too bad there isn't a ped / bike 'shortcut' to Loring park Greenway from below Freeway-
Perhaps continue Bryant bike/ped bridge to a little Street named 'Dell'?
Hennepin S exit is already starting to rise, so it would have to loop East.

Getting the Skyway closer would be great, too.

[RailBaronYarr]

How many flyovers have great pedestrian scenes beneath them? I highly doubt this would be the optimal solution for connecting the areas.. I also doubt that the reason people aren't making the trek is because there's a lack of skyways. People walk up and down the whole uptown area without them.

[UptownSport]

Well, you could watch all the crashes on 94 at rush hour ...

Bad idea, there just wouldn't be room, Bryant bike bridge is buried.

[Nick]

http://www.startribune.com/local/minnea ... 13931.html

Lowry Hill Tunnel crashes spark safety concerns

TIM HARLOW, Star Tribune May 5, 2013 - 8:43 PM

MnDOT is discussing how best to improve safety for the 153,000 motorists who pass through the tunnel each day.

A concrete median is all that separates the traffic on I-94 at the east end of the Lowry Hill Tunnel. On Wednesday, it wasn’t enough to stop a speeding westbound semitrailer truck from jumping the 32-inch-high barrier and setting off a crash in the eastbound lanes involving at least three vehicles, including one that rolled over.

No one was seriously injured in the crash, which occurred in rainy weather about 5:30 a.m. and tied up traffic for hours.

A similar scene played out in February when a milk tanker struck the same barrier and flipped over. In 2011, a semi carrying car parts overturned, killing the driver.

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