I believe the lower level only goes up to Grand Ave.

I'm not following. Is your idea that riders on the 147 could have the driver stop at Barry so they could walk to Belmont Harbor? What's the point of the intermediate stops?

Pretty much, yeah - good example. The Belmont station would be at Barry because that's where the underpass is. The 77 already turns onto the Inner Drive, so it would be easy to switch to an east-west bus. The area around the Belmont/Barry station is high density and if every bus on Lake Shore Drive stopped there, this would give Lakeview residents a variety of quick trips to downtown, depending on which bus they board at the station.

Lake Shore Drive acts as a rapid transit line, with each bus entering and exiting at a different point. The highest frequencies would be south of Fullerton.

http://farm3.staticflickr.com/2852/9...81d30bce_z.jpg
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I am not seeing the benefit of BRT along lakeshore drive when people enjoy the convenience of picking up the 135/136/148 etc. in front of their buildings, especially in the winter. Why walk the extra distance to a bus stop in the middle of drive when I only have to walk 10 feet in front of my high rise?

A bus only lane shared by all northside buses or a new subway running south to Hyde Park would be a different story.

This would totally be a dream come true to me.

Curious, what is the thinking regarding the portals? Going south, presumably it slopes up and then bores through the Grand wall into Lower Michigan? What about the north end?

Construction would be colossally disruptive - is running it under Rush an alternative?

Well, my thought is to just continue Lower Michigan north from Grand to Oak. Only 42 feet wide, under the center medians of Upper Michigan Avenue (128 feet wide), very shallow cut-and-cover with simple open grilles in the driving lanes of upper Michigan for ventilation. The transition to Lake Shore Drive would come when the interchange at Oak is rebuilt.

At the south end, it's a little trickier. You can get in and out by looping through Illinois Center or Garland-Lower South Water, but that gets ugly with articulated buses. Probably better to do one-lane access ramps in the center of Michigan: a northbound ramp down between South Water and Lake, and a southbound ramp up between Lake and Randolph.

Slopes up? We're not talking San Francisco here.

Oak Street at the north end. That whole interchange needs to be rebuilt someday anyway.

That's probably the dumbest idea I've ever heard. "Let's spend the same amount of money and create something way less efficient and convenient." No.

There'd be no getting around some disruption along Michigan Avenue, but crossings disruptions could be kept to a minimum, and if it was done all in the median, or all on the outside lanes, it could be mitigated pretty well.

I mostly agree with Mr. Downtown's assessment, although I think there should also be a portal to State Street between Wacker and Lake. That would be more controversial and tricky with the Red Line, but I think quite possible and then allow both the State Street and Michigan Ave buses to use portals. And of course there would be buses using Lower Wacker. And ideally you'd get Metra to let the CTA run a few routes through the bus transitway along the Metra Electric tracks.

We're talking a 1-level slope, like all the other 1-level slopes resulting from roadways approaching a Chicago River crossing. Lower Michigan is on the same grade as most of the rest of North Michigan (beyond Ohio), so the tunnel would involve a slope from grade to the new subterranean level. It's a topographical observation and there isn't really much more or less to it.
Let's spend the same amount of money, not screw an entire quadrant of downtown with traffic nightmares for a couple years while shooing away shoppers and tourists, and create something slightly less convenient but better in spreading out crowds and encouraging the next wave of development one block off Michigan. There are many cities in the world where the marquee shopping district is offset a block or so from the main transportation spine. And I think you are underestimating the scale of the project and its disruption - are you familiar with where sewer lines and other utilities run, or with whether excavating a half-mile trench into earth (including rerouting new utilities underneath it) is for example simpler than the multiyear all-above-ground, mere-replacement Wacker project? In addition, construction closures would take up more than just the center medians, to say nothing of the couple stations and all their access portals, and any emergency egress portals along the route. I'm not saying it's an unacceptable idea, nor that there is an elegant way to get from Rush to LSD, but I don't see it as the only option and could see a lot of chamber of commerce style opposition from some of the most powerful landowners (and commuters) in the city - some of whom probably would view the finished bus tunnel as a net negative for Boul Mich anyway.

There are a lot of utilities under Rush, too, and Rush is barely wide enough for two buses, plus it angles away from Michigan a bit between Chicago and Oak, plus it has a fair number of high-end retailers between Pearson and Oak, not to mention that along Oak - the likely connector to LSD - there's plenty of money.

Michigan is the only street in the area that could plausibly remain open - albeit at reduced capacity - during the construction. It also already connects to the other below-grade streets that would be incorporated into the network (Illinois, Carol, Wacker, etc).

When Paris built Metro Line 1, which runs under the Champs-Elysees and around the Arc d'Triumph, it was built with cut-and-cover. I believe the same is true for the subway under Gran Via in Madrid and under Passeig de Gracia and La Rambla in Barcelona. Sometimes the end does justify the means.

Why not just bore the the tunnel? Two small-diameter tunnels (~18') bored from Lower Michigan at Grand to a pit in the Michigan/Oak park. You'd still have to build the stations with cut-and-cover techniques, but that's only 4-6 blocks' worth of disruption, depending on the number and length of stations, versus the entire length of N. Michigan.

If the tunnels are deep enough, they would avoid most utilities except certain sewers. Perhaps the vertical alignment could be tweaked to avoid them. :shrug:

I've never heard any official suggestion of a Michigan bus subway; has there been such a suggestion from city or regional officials?

Maybe I'll sound stupid saying this but I can't see how closure of most lanes would have any severe consequences on Michigan Ave. Businesses depend on pedestrian traffic, and commuters rely on buses getting through. Taxis and cars can still get close to Michigan ave on cross streets. Only time Michigan Ave is backed up is Friday afternoons. Otherwise people take other routes to get around. It seems like when Michigan Ave was totally ripped up almost 2 years ago it wasn't that big of a deal. Reduce it to two very narrow lanes each direction and choreograph construction.

How are you going to ventilate a bored, deep-level tunnel with diesel buses running through it every 40 seconds? Just restrict turns for a 1200-foot section, close the two center lanes, vibrate in the sheet piling, and excavate. Six weeks later, deck it over and move on. It's critical that it be close to the surface for ventilation, to avoid water infiltration, and so most people will use stairs to and from boarding platforms. Also so you can use the existing lower-level roadway between Grand and Lake.

I was thinking something along the lines of Boston or Seattle, where they used dual-mode buses and strung trolley wire in the tunnels. You'd still need ventilation in the stations but as you mention, that could be done using grilles to the open air above.

I agree.

This discussion needs more visual aids.

CTA trying for more 'customer-friendly' seating in future cars

http://www.chicagotribune.com/news/l...0,686396.story




http://www.chicagotribune.com/media/...8/76882524.jpg

The new Ravenswood Metra station taking shape:

Also of note: further west down Lawrence, closer to Damen (sorry didn't get a shot) I believe you can see work on the road diet getting underway. I believe they are currently ripping out the old streetcar rail.

http://i.imgur.com/O5MwzlF.jpg

Jeez, they've got that horrible horrible Metra logo embossed in the concrete? Why? Why Metra why?

^ That is funny.

Just to finish my thoughts on this, and play devil's advocate, based on scale Rush probabalistically has fewer utility issues than Michigan, although east-west-running utility problems would likely be the same. As for width, you're trying to have it both ways if you say a small median in Michigan would be sufficient for this project, but suddenly the entirety of Rush is inadequate. As for geometry, a Rush alignment would have issues but at Connors Park there would be ample space to lay out a bowed curve to Delaware. Delaware to Michigan would be tighter, but nothing different from what buses do on surface streets already. On Delaware, you basically have 2 giant structures (900 and Fourth Church) plus a couple others, so only a handful of landowners (I think the 900 condos entrance is on Walton). Then there's only 1 more block until Walton; Michigan beyond Walton will presumably be chopped up anyway for the big LSD project. Connors Park could even sit on top of a comfortably-sized, easily-constructed station.

The thing about Rush is that you could darn near shut the whole street down for a month and barely anyone would notice, other than the limited establishments on it. The south end is tricky, but somewhere within a block of Hubbard, including that giant surface lot, there may be space for a portal. Because most of North Bridge is elevated, the future developer of that parcel might be happy to sell or rent the portal incursion onto the parcel.

Hayward, I think you're pretty off base in your assessment of dieting Michigan to just a couple lanes. Think of rainy commuting hours, or snowy Saturdays or evenings in the dark winter. For example, getting a cab from the Loop to and from a doctor's appointment east of Michigan can already be a nightmare and unpredictable in rain during the day. The big problem is not whether the adjoining retailers lose vehicle-arriving customers, it's whether the surrounding street grid has arteries to handle the displaced traffic flow.

Mr Downtown, them construction types are going to want a buffer lane, especially for equipment, on each side of your median trench during construction, so it feels more like 3 or 4 lanes being shut down.

Anyway, given Mr Downtown's comment about 1200 feet sections, it does seem much less disruptive if they did the center-median Michigan closures just 2 or 3 blocks at a time and suspended parking lanes nearby to allow for efficient detours, and also gave the avenue a breather during certain congested times of year, like December. So I hope that would work out somehow. I think this concludes my outside-the-box suggestion for now.