So why bother then? If they still need to direct traffic out of the city why not do that anyway and leave the old structures just for local traffic not passing through on the interstate?

It would require a visit to Boston to understand, I imagine, but to the best of my knowledge the old I-93 viaduct was dropping to bits anyway and needed replacement. It was also carrying over 170,000 vehicles a day.

The viaduct severed the city into two halves, and was an hideous eyesore. Imagine a Westway style flyover cutting right down the middle of any major city's high street and you had I-93. It was deemed so ugly that even in the 1960s the final stages were built in a tunnel (around Dewey Square).

In order to built I-93 in the mid 60s, 2000 historical buildings of downtown Boston were destroyed. Some of them were as old as 1690... So an ugly elevated greenish viaduct was built to get the 6-lane interstate across Boston.

But complementary to this, there were other projects:
* to route the I-95 across downtown the same way the I-93 did. This was finally abandonned in the 1970s after several trials, and the I-95 was rerouted around Boston orbital. This is very obvious when coming from NYC and heading to Boston: the northbound carriageway is reduced to 1 lane!!! and then does a 270° curve on the incomplete cloverleaf interchange with the orbital in order to reach it. A true bottle neck, also most traffic uses I-93 instead (hence the Big Dig tunnel)
http://maps.google.com/?ll=42.207477,-7 ... 014462&t=k[/url]

* a downtown orbital (I-695 if memory serves), which would have skirted around Boston's business center.... Project aborted in the 1970s with the I-95 inside town...

Read "The Roads that built America" for more infos!!!

After all the years of detours and road constuction. the work is almost done. Well, except for the occasional leaks in the tunnels. A small bit of engineering indeed but worth it. A trip from Central Massachusetts to Logan Airport would normally take 1.50 hours which has no been reduced to 50 minutes. Exit ramps directly from Interstate 90 take you directly into the airport. No more surface roads! Yeah. A big blessing in disguise. Pretty much all that is left is some finish work on the surface roads and then the actual work to be done on the Rose Kennedy Greenway

http://www.masspike.com/user-cgi/news.c ... e&src=news

Spring update on the Big Dig with some great pictures of what it originally started off as and the end result. Happy to report that you here of very very few traffic issues now on I-93 from the South Shore to Nort of Boston. Well worth all of the grief and aggrevation!

http://www.masspike.com/bigdig/updates/spring2006.html

You can add Pasadena and Baltimore to that too. Basically, it's only historic areas where there is a protest against this as, in most cases, an urban motorway involved flattening a lot of low-income housing which was left after the "white flight" from the city centres. DC has a through freeway -- the 295 and 395 -- but obviously there won't be a 6-lane on the White House Lawn. However, through traffic will take the Beltway, and beltways exist around most major cities, even if they have a through interstate.

It's a sensible idea -- look at the efforts made to make the A40, A12, and A13 into GSJ-ed D2s and D3s and the bitching everyone gives about the signalized right turns.

I think it's Washington's I-395 which stops on a T-junction with traffic lights after series of covered trenches and tunnels, because it was never completed.
Same deal in Newport, RI, where a beautiful viaduct end on a 1-mile section of the meant to be I-895 between Newport and I-95, and on the other side the freeway ends onto the US-1 and fails to reach I-95...

Found in AAA Horizon magazaine. AAA is a large motoring club here in the States. Numbers are according to the Massachusetts Turnpike Authority, managers of the "Big Dig"

"The average traffic speed on I-93 Northbound has increased 10 mph before the prjoect began to 43 mph"

"Average afternoon peak hour northbound travel time on I-93 northbound through downtown (Boston) has dropped from 19.5 minutes to 2.8 minutes"

A couple of impressive numbers and well worth all of the grief and aggrevation. Perhaps a SABRE awaday to Boston is due??

That Bunker Hill / Leverett Bridge approach is just fantastic, you can tell the designers had "Hot Wheels" sets when they were kids

I drove the big dig last year having driven through Boston a few times previously and was hugely impressed with the result - well worth the upheaval - and I'd recommend the area to anyone considering an international awayday/week, taking in Newport and the Jamestown bridges whilst you're at it.... as a slightly OT aside, some of these fantasticly massive steel construction bridges around New England and further north around Buffalo and the St Lawrence Seaway must be coming to (or have flown miles beyond) their design life - are any programmed for complete replacement in the foreseeable future?

An old bridge in Maine (northern New England) is being replaced...here's a website:

http://www.waldohancockbridge.com/waldo-county-bridge/

There has been a collapsein the Boston Big Dig killing the occupant of a car trapped under 12 tons of concrete.

MB

The Ted Williams Tunnel (named after a famous Boston Red Sox baseball player), has been shut down completely, as there are now dozens of similar parts of tunnel roof with the same "problem" as the part that collapsed. City, State, and the Federal governments will have to keep their fingers crossed, and hope it is not a design flaw. The Ted Williams Tunnel is the oldest part of the "Big Dig", so, it would be logical if the problem occured there first.
I am sure that the Lawyers will be very busy over this.

It should be noted that it is not the Ted Williams Tunnel that is shut down, but a connector tunnel on Interstate 90 this is closed prior to the Ted williams Tunnel. Traffic exiting from Logan Airport heading east is allowed to travel thru the Ted Williams Tunnel and then is rerouted after exiting the Tunnel.

"Megastructures" (Channel 5, Monday Aug 20th, 8pm) is about the Boston Big Dig

It is a repeat, so apologies for bumping this thread to those who have already seen it

Just watched it, amazing tunnel, but I can't help thinking all that money put into another part of the cities infrastructure would be more useful!

I don't know if any have been following the news but they have been having problems with the light fittings in the Big Dig tunnel.



Big Dig lighting problems continue

Big Dig Tunnel Light Removed Because Of Corrosion

Editorial: Problems at Big Dig require quick reporting

It wasn't just the freeways that were put underground. Boston had an extensive network of "elevated" rapid transit lines, which had been built (100 years ago) on steel structures over main radial streets (and which completely blight such streets). Several US cities went for this at the time. Manhattan cleared them out in the 1950s (they remain in other New York boroughs, along with several other US cities), but Boston has got rid of most of them underground as part of this project.

Note that Boston has also long had multiple Interstate ring routes (Interstates 95 and 495) around the urban area, and one of the more comprehensive rapid transit networks in the US. It also has one of the largest airports in the USA, which is virtually in the city centre, and which generates huge access needs. But as a result it has retained the vitality of its central core as much as Manhattan and San Francisco, and unlike most US major cities, which placing the freeways underground contributes to. Note that both these other cities have also demolished elevated roads in their centres as well.

To be fair I I don't think it's just the USA, many countries have, it's simply that the USA is so much larger in terms of population/wealth and has been for so long that it is the prime example, while the UK sits probably at the more conservative end of the spectrum in regards to urban motorway building. South Africa followed the American example with urban freeways in all three of the largest metropolitan areas plus Port Elizabeth, though of course on a smaller scale. Many other countries did too.

They didn't just build them through/near the centres, in most cases American cities have outer bypass routes (sometimes multiple) as well as urban ones, to allow access to the city centres plus to allow long distance traffic to bypass them.

I wouldn't advocate wholesale bulldozing of historic districts for road developments, but in my opinion the attitude in Britain has swung to the sentimental extreme and of overvaluing architecture that is extremely common in the country and therefore blocking useful schemes.... often the attitude seems to be that some very common late 19th century buildings are worthy of the protection afforded to extremely rare historical gems.

Hmmm, check your timeline. The last of the old elevated sections of line, the Orange Line's Washington Street El, was torn down in 1987. It wasn't part of the Big Dig, though some stations on the Orange Line were renovated as part of the project.

The introduction to the Wikipedia article says that 'Initially, the plan was also to include a rail connection between Boston's two major train terminals'. Perhaps that's what WHBM was thinking of?

I gather from Wikipedia that, aside from aesthetic concerns, the benefits of the project are not limited to widening the north-south route - perhaps more important, east-west traffic has been taken off it. It's as though you built the M74 completion and widened the M8 through the city centre, with the cherry on top that every motorway in Glasgow is put underground!