Constructing Freeway Tunnels

[Rothman]

My older brother recently read about the history of Boston's Central Artery; how it came to be and what the areas were like prior to its existence.  Long story short; had the Artery never been built, areas like the Financial District as it is today would have probably never come to fruition... at least not in Downtown Boston.

What's the long story?  It's no secret that urban freeways frequently were bulldozed through neighborhoods considered undesirable.

[PHLBOS]

My older brother recently read about the history of Boston's Central Artery; how it came to be and what the areas were like prior to its existence.  Long story short; had the Artery never been built, areas like the Financial District as it is today would have probably never come to fruition... at least not in Downtown Boston.

What's the long story?  It's no secret that urban freeways frequently were bulldozed through neighborhoods considered undesirable.

I'm not denying such; the story he read indeed even mentions that.  The very reason for the Dewey Square/South Station Tunnel was a compromise alternative to an all-elevated structure. 

Nonetheless, if an area becomes so inaccessible to vehicles that goods and services can't either reach/serve the area or pass through in an efficient manner; its long-term economic pulse is not going to bode too well.

[roadman65]

Look at the results of what freeways do.  In Orlando you can tell how I-4 effected that city as the interstate is a dividing line between residential and industrial between FL 408 and Michigan Street.  Then in Downtown Orlando, east and west of I-4 you have totally different types of neighborhoods.  You have the modern financial district to the east of I-4 and then a poor neighborhood to the west side of it with older urban buildings occupied by those who are under the poverty line.

Freeways whether above ground, below ground, and at grade separate and rearrange zoning and demographics.  To hide them is the only way to save neighborhoods, thus by tunneling whether cut and cover or bore is the only way to save them.

[kkt]

The disadvantages Phlbos points out are true, however I still think some new tunnels will be built.  Populations and driving in urban areas continues to increase.  During the prime freeway building era of the 1950s-1960s, inner cities were mostly poor people too busy struggling with daily life to organize in opposition.  Now, inner cities include some high-rent and middle class housing with people who do know how to fight back.  Tunnels are a way to accommodate increased traffic without wrecking dense urban neighborhoods, so they will continue to be built.

[PHLBOS]

Believe it or not, the original Central Artery actually saved the North End neighborhoods.  Its barrier-like presence kept the newer-style development from encroaching.  Such was probably one reason why most of the land where the Artery once stood is now the Rose Kennedy Greenway.  The last thing many North End residents & businesses wanted was to have their neighborhoods trounced/invaded by mega-development once the Artery went away.

[PHLBOS]

Tunnels are a way to accommodate increased traffic without wrecking dense urban neighborhoods, so they will continue to be built.

The opening of the Big Dig tunnels in Boston was over a decade ago (hard to believe); could you cite me one example of a tunnel-like freeway opening in the U.S. since then?

[roadman65]

No I cannot believe the Big Dig is over a decade old, but I also cannot name one project of similar nature since that time unless the Dallas tunnel was constructed since then.

[TheStranger]

Tunnels are a way to accommodate increased traffic without wrecking dense urban neighborhoods, so they will continue to be built.

The opening of the Big Dig tunnels in Boston was over a decade ago (hard to believe); could you cite me one example of a tunnel-like freeway opening in the U.S. since then?

US 101 through the Presidio in San Francisco for one mile/two tunnels, which opened a month ago!

In a more serious example, I-635's HOV lanes between I-35E and US 75 in Dallas are essentially underground aren't they?

[roadman]

During the 2004 DNC Convention held in Boston; the newly-opened I-93/O'Neill Tunnel (that replaced the Artery) was closed to all traffic due to security reasons.  IMHO, had the Artery still been present; it would've only had a smaller segment of it closed or it wouldn't have been closed at all.

During the week of the DNC, the Zakim Bridge and O'Neill Tunnel were completely closed ONLY during those times when the convention was in session.  The rationale for completely closing the tunnel for the full length was not because of a possible or perceived threat against the tunnel itself, but because establishing a roadway closure inside the northbound tunnel at the Government Center exit would have been impractical.  Additionally, there would have been problems routing the northbound traffic around the 'exclusion zone' at the Fleece center (not TD Garden) on local streets once they left the tunnel.  At the very least, I'm sure the North End folks would not have liked that.

And of course, all these impacts could have been avoided were it not for the arrogance of the DNC and the media, who decided that the then-newly opened convention center in South Boston was not an acceptable venue - despite the fact that the floor of Fleece Center had to be completely re-configured for the week - then put back into its original configuration.

I strongly suspect that, had the original elevated Artery still been in place at the time of the DNC, that northbound through traffic would have been detoured off in the vicinity of South Station, and that only traffic bound for the Callahan Tunnel would have been allowed north of there - due to the issues with traffic on local streets I described above.  Southbound through traffic would have likely been detoured off at Sullivan Square, with southbound traffic for the Tobin Bridge allowed to continue down the Lower Deck.

[roadman65]

Speaking of the tunnel in Boston, according to Googlemaps they are showing that the NB I-93 ramp to Storrow Drive goes directly beneath the former Boston Garden.  Is that true or an inaccuracy by Googlemaps?

[roadman]

Speaking of the tunnel in Boston, according to Googlemaps they are showing that the NB I-93 ramp to Storrow Drive goes directly beneath the former Boston Garden.  Is that true or an inaccuracy by Googlemaps?

Although Googlemaps exaggerates the alignment somewhat, the ramp does indeed 'clip' the northeast corner of the TD Garden building.

And one correction - the TD Garden building (originally the Fleece - er - FleetCenter) was constructed behind the original Boston Garden.  Where the Garden used to be is now a parking lot, although there's now plans to build a combined retail, office, and residential development - including a supermarket.  Alas, however, there are no plans to include a direct connection from the commuter rail platforms to the Green Line/Orange Line subway station as part of the structure.

[Bruce]

IIRC, there was once a plan to build a federal courthouse on a lid over I-5 in Downtown Seattle that was canceled because of security concerns.

[Pete from Boston]

And one correction - the TD Garden building (originally the Fleece - er - FleetCenter) was constructed behind the original Boston Garden.  Where the Garden used to be is now a parking lot, although there have been unfulfilled plans for decades now to build a combined retail, office, and residential development - including a supermarket.  Alas, however, there are no plans to include a direct connection from the commuter rail platforms to the Green Line/Orange Line subway station as part of the structure.

FTFY.  There was a new North Station public area required as part of any development there, but the MBTA, tired of waiting, traded that away for the dim compromise we have today.

[kkt]

Tunnels are a way to accommodate increased traffic without wrecking dense urban neighborhoods, so they will continue to be built.

The opening of the Big Dig tunnels in Boston was over a decade ago (hard to believe); could you cite me one example of a tunnel-like freeway opening in the U.S. since then?

Caldecott Tunnel 4th bore
http://www.dot.ca.gov/caldecott/

on Saturday, November 16, 2013 the Caldecott Fourth Bore opened to traffic — on time, under budget, with little fanfare.

[vdeane]

I live in the Green Bay area and there is no freeway access to Downtown Green Bay.  It should be set up perfectly like some urban planners want.  Surface streets with pedestrian access.  If it's so great, why is Downtown Green Bay struggling while the areas along the freeways are thriving and attracting development? 

Lots of factors, not all of them road related.  There's the matter of what kind of development.  Mixed use, compact development is generally desired these days, and typically doesn't develop on the interstates.  Strip malls, neighborhoods of cookie cutter houses, and general sprawl aren't in fashion.  Plus not every surface street is pedestrian friendly.

[froggie]

Strip malls, neighborhoods of cookie cutter houses, and general sprawl aren't in fashion.

...and also tend to be more expensive on a per-unit basis to provide infrastructure for.  Sure, infrastructure in a dense area is expensive, but not on a per-capita level.

[PHLBOS]

Caldecott Tunnel 4th bore
http://www.dot.ca.gov/caldecott/

on Saturday, November 16, 2013 the Caldecott Fourth Bore opened to traffic on time, under budget, with little fanfare.

Good to know and an interesting read.  However, there's a few items worth noting:

1.  This particular tunnel was built as an expansion to an existing parallel tunnel system; similar (in concept) to what Boston's Callahan Tunnel is to its older Sumner Tunnel companion.  Prior to the Callahan opening in 1961; the Sumner was a 2-way tunnel paved with cobblestone.

2.  The listed length of the Fourth Bore Tunnel is 3,348 feet (just over 5/8 mile) which is much shorter than Boston's I-93/O'Neill Tunnel and has no interchanges located inside the tunnel itself.  In short, it's more of a traditional tunnel crossing (nothing wrong with that) vs. a tunneled highway; which, I believe, was the OP's premise for this particular thread.

3.  It's not located in a city.

4.  Topography was the main reason why tunnels (the Fourth Bore and its older companions) were chosen for that area.

In hindsight, I should've quantified my earlier question regarding tunnels that have opened (or being constructed) since Boston's Big Dig and specified tunneled freeways/expressways/networks as opposed to just tunnels (simple mountain/plaza/water crossings) in general.

That said, tunnels do have their place and purpose (I don't believe that anyone here is disputing such); but the notion that every highway that goes through a major city can be tunneled is pure fantasy.  Short stretches/segments of tunnels might be a more realistic outcome. 

One needs to keep mind that long before Boston's Big Dig was even thought of; other areas explored the possibility of tunneled highway options but either dropped them or scaled back the tunnel portion due to cost reasons even then.  I-95 through Central Philadelphia is an example of such.  A full-blown tunnel option was contemplated during the early 60s but was dropped in favor of the current bathtub design (which made provisions for a future cap for the middle opening) due to cost reasons.

[Rothman]

My favorite never-done-tunnel-proposal was US 9 under Washington Park in Albany, NY.  It's a nice big freeway from where its stub hits where the portal was supposed to be up to Loudonville -- about a mile -- a nice big freeway that is now overbuilt for the traffic that's on it.

[Henry]

Good luck capping the Downtown Connector in Atlanta! It would have to be the most expensive project ever undertaken, given the highway's width (16 lanes) alone.

[kkt]

The Big Dig is a uniquely complicated tunnel with many exits and entrances and an interchange.  I don't think there's been anything really comparable before or since.  However, the original implication that no new freeway tunnels will be built just isn't the case.  They are expensive and unusual always, and the era of rapid freeway building that we had from the 1950s to 1970s is over, but even so the Big Dig didn't keep Seattle from starting its tunnel project.

[TEG24601]

The Alaskan Way Viaduct replacement debacle has show that it's smarter to split up freeway tunnels into two smaller tunnels instead of going all-in. I would've preferred the temporary mess of a demolished viaduct and cut-and-cover construction instead of waiting on Bertha.

They were going to do the cut and cover first, albeit, two lanes each way, demolish the viaduct, build the additional 4 lanes.  It would have solved the whole seawall mess as well.


As for I-5, I think if we simply get the roadway off of those bridges, and cut it into the hillside, then a simple hill cover would be a great thing, but with the current layout, it seems a bit messy, when it does come to replacing the roadway.

[TEG24601]

Good luck capping the Downtown Connector in Atlanta! It would have to be the most expensive project ever undertaken, given the highway's width (16 lanes) alone.

They did it on I-696 near Detroit on its journey between 11 and 10 mile, without much difficulty (10 lanes).  Add some supports in the Middle, and covering 8 at a time should be a cakewalk.

[Pete from Boston]

The Big Dig is a uniquely complicated tunnel with many exits and entrances and an interchange.  I don't think there's been anything really comparable before or since.  However, the original implication that no new freeway tunnels will be built just isn't the case.  They are expensive and unusual always, and the era of rapid freeway building that we had from the 1950s to 1970s is over, but even so the Big Dig didn't keep Seattle from starting its tunnel project.

Massachusetts just rejected the Olympics in part because we have a culture that doesn't seem to be able to control the number of hands dipping into the big pots of money in large projects.  Ours might not be the best example to base future decisions upon solely.

[kkt]

The Big Dig is a uniquely complicated tunnel with many exits and entrances and an interchange.  I don't think there's been anything really comparable before or since.  However, the original implication that no new freeway tunnels will be built just isn't the case.  They are expensive and unusual always, and the era of rapid freeway building that we had from the 1950s to 1970s is over, but even so the Big Dig didn't keep Seattle from starting its tunnel project.

Massachusetts just rejected the Olympics in part because we have a culture that doesn't seem to be able to control the number of hands dipping into the big pots of money in large projects.  Ours might not be the best example to base future decisions upon solely.

I hope you're not advocating for Seattle to host an Olympics? 

[Bruce]

The Big Dig is a uniquely complicated tunnel with many exits and entrances and an interchange.  I don't think there's been anything really comparable before or since.  However, the original implication that no new freeway tunnels will be built just isn't the case.  They are expensive and unusual always, and the era of rapid freeway building that we had from the 1950s to 1970s is over, but even so the Big Dig didn't keep Seattle from starting its tunnel project.

Massachusetts just rejected the Olympics in part because we have a culture that doesn't seem to be able to control the number of hands dipping into the big pots of money in large projects.  Ours might not be the best example to base future decisions upon solely.

I hope you're not advocating for Seattle to host an Olympics? 

The last thing we need is an Olympics with tons of new and soon-to-be-underused venues. Give us a few World Cup group stage matches or a one-off Super Bowl and we'd probably be able to cope (with massive planning ahead of time).