A new bridge across the Mississippi at St. Louis! After years of wrangling and controversy, it was finally happening.  The Mayor proclaimed the bridge to be “an advertisement to the world that St. Louis is determined to move forward with the other great cities of the country.”

Those words could describe the new I-70 bridge under construction over the Mississippi north of downtown, but they were published almost 100 years ago, describing the St. Louis Municipal Bridge, later renamed the MacArthur Bridge. If you’re uncertain as to where the MacArthur Bridge is, it’s just south of the Poplar Street Bridge. It was closed to automobile traffic in 1981. It still carries rail traffic, but it is a rusting hulk of its former grandeur.

From the east, the auto approach departs Piggott Avenue in East St. Louis, soars over streets like Paradise and Victory Avenues and then abruptly ends in mid air seven blocks later. The truncated approach on the west side of the river begins at 7th street and continues across the river, but it is inaccessible to regular traffic.

Beneath the road deck is an active railroad deck, fed by a tangle of approaches that weave a black, industrial web. Mounds of rusting metal chips surround the footings of the bridge. Those chips used to be part of the bridge.

Great structures, designed to nurture future prosperity, often end up like the MacArthur Bridge — grand in their day but now sad, decaying monuments to the past.

Ever wonder what the new I-70 bridge will be like 100 years from now?

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In August 2010, gaping holes opened up in 14 bridges along 4.5 miles of I-93 in Medford, Massachusetts, a crucial commuter corridor for the Boston area. There was no alternative but to replace them—all of them. Normally, tearing down and replacing that many structures could take as long as four years and would certainly cause horrendous traffic tie-ups for the 200,000 drivers who traverse that stretch of I-93 every day.

So, Massachusetts’ Department of Transportation [MassDOT] decided to try something new. The result is “Fast 14,” an innovative and aggressive project that is replacing all 14 bridges, not in four years, but in a single summer, at a cost of $98.1 million [80 percent of which is federal money, of course.]. And they’re doing the whole job on a weekends-only schedule.

How can they do that? Basically, they’re re-inventing bridge reconstruction. Rather than building and pouring concrete for the bridge supports and decks on site, MassDOT is having everything pre-fabricated and then assembling the bridges like giant Lego projects. Once the infrastructure is in place, they surface the decks with a quick-drying substance, paint the lane stripes, and voila. [Right. It’s undoubtedly not that simple.]

All of the demolition work and necessary lane closings take place on weekends, using a precisely choreographed procedure that creates the work space between 10 pm on Fridays and 5 am on Mondays. The work focuses on a different bridge each weekend. To get a better idea of the process, watch this video about Fast 14. [Full disclosure: It’s got a somewhat promotional tone, because MassDOT and USDOT are very proud of this project. But it gives a good explanation of how the work is being done, and how the scheduling works.] The project began in June 2011 and, as of mid-July, it was on schedule, with half of the bridges already replaced.

Not being a Boston commuter, I can’t comment on how this whole thing is going over among the locals, who are being warned, every week, to plan ahead, if they’re going to a Red Sox game or another downtown event.  I do know that, when my summer-travel itinerary required my family to drive from Boston’s Logan Airport to points north—on a Saturday afternoon in July—we got stuck in a very long jam. With two I-93 lanes closed, we inched along about 6 miles in an hour. We weren’t happy, but we weren’t in a commuter hurry, either. And when I got home and learned about Fast 14, I felt better about the whole thing: It’s infrastructure; it’s jobs; it’s good old-fashioned ingenuity at work; and it’s for the common good [if you believe that safe bridges and smarter highway construction—or highways in general—are about the common good. Some of which may be debatable.]

Anticipating a similar snail’s pace for our return trip on the next Saturday, we factored in an extra hour. But we didn’t need it: At 2 pm, Northbound I-93 traffic still looked terrible, but our two southbound lanes flowed freely. I can tell you one thing: I wouldn’t want to be a Boston driver on that stretch if they were doing this work in the conventional way. All hail MassDot and radical thinking [said the outsider].

[Image credit: MassDOT]

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