Signature Mississippi Bridge receives a $640 million solution.
By Andrew Gates

When U.S. Secretary of Transportation Ray LaHood, joined by a dozen federal, state and local officials, shoveled Illinois and Missouri soil together to start construction on the New Mississippi River Bridge in St. Louis, it was more than just a celebration. It was a symbol of nearly 20 years of cooperation, commitment and compromise needed to address a growing regional transportation need in the greater St. Louis metropolitan area. In 1992, regional officials identified a new river crossing as one of the largest infrastructure needs in the St. Louis region, an area encompassing three counties in Illinois and four in Missouri. This new bridge is needed because of congestion on the Poplar Street Bridge, or PSB, crossing the Mississippi. The PSB is a major transportation artery across the river. It carries three interstates (I-70, I-55 and I-64) and currently has too much traffic on it. Bringing three major interstates across one bridge creates a natural chokepoint for the region. A crash or maintenance work on the bridge can create backups for miles. Studies determined conditions on the PSB would get worse as traffic levels continued to increase. Traffic engineers predicted that PSB traffic levels would rise to more than 150,000 vehicles daily by 2030 if nothing was done. "The regional transportation planning organization commissioned a study and determined that the best way to improve traffic flow in the region was to build a new bridge across the Mississippi and to relocate I-70 onto that new bridge," said Greg Horn, P.E., New Mississippi River Bridge Project Director. "The two state departments of transportation started work to determine the location and the environmental impacts for a new bridge." That location study was finished in 2001. The conceptual design for the new crossing, based on that study was a 2,000 foot, eight-lane main span cablestayed bridge with 500 foot towers about a mile north of the Poplar Street Bridge. This design included a number of other improvements to keep regional traffic flowing.

The price tag on the new bridge was roughly $2 billion _ much more than both states could afford even for a project with such regional impact as this. "We had to look at how we could cut costs to make this bridge more affordable, so we started redesign work to reduce costs," Horn said. The next conceptual design, completed in 2005, was estimated to cost about $1 billion. Even with a 2005 Federal Transportation Bill appropriation of $239 million _ the largest appropriation ever for a single project _ the two states were still unable to put together funding for a new bridge. "From that point, the two states worked together to determine how to pay for this bridge project," said Horn. "Both states brought forth proposals to the table. We looked at establishing a public-private partnership that would charge tolls; we looked at a companion bridge project for another local bridge; and we looked at different locations and a variety of other options." Finally, in early 2008, the two states came to a $640

million solution that met the regional needs and could be funded. The solution was to build this project in phases. The first phase would construct a four-lane, 1,500-foot span bridge that can be expanded to six lanes by restriping in the future as traffic levels demand. This project should adequately handle traffic for the next 20 years, and it is also being designed to be compatible with a future companion bridge (the second phase), which will add another four lanes when traffic demands and more funding are available. As part of the bi-state agreement, Missouri would manage the design and construction of the river crossing. Each state would take responsibility for the construction on their side of the river. Illinois committed $313 million for their portion of the bridge and three miles of roadwork on their side of the river. Missouri committed $88 million for their share of the bridge and one-half mile of roadwork on their side of the river. By including the $239 million Federal appropriation, the two states could fund the

project and start design work. With funding in place, the process to design and start construction on the bridge project was fraught with its own challenges. One of the biggest was the numerous agreements with railroad partners on the project _ five in Illinois and one in Missouri. "The Illinois Approach, the section of bridge leading up to the main bridge, spans 17 tracks," said Gwen Lagemann, P.E., Illinois Department of Transportation programming engineer for the New Mississippi River Bridge. "Each of the 11 piers is on railroad property. We worked closely with the railroads for more than two years to make sure our design was acceptable to all parties." Besides coordination with the railroads, the project management had to coordinate four major sections of the project. These sections were natural

breaks in the project and included: the cable-stayed bridge; the Missouri interchange; the Illinois trilevel interchange at I-55, I-64 and I-70; and the connection between that Illinois interchange and the bridge. During design, Illinois added $60 million for an interchange between the I-70 connection and Illinois Route 3. Due to size and complexity, each section was designed by a different firm, which meant that adjustments on one project needed to be communicated quickly with the firm working on adjoining sections. "One of the biggest successes during this project was having a co-located office to design the cable-stayed bridge and the approaches," said Horn. "We had many of the major players together in one location: HNTB,

who designed the cable-stayed bridge; CMT, who designed the Missouri interchange; MODOT; IDOT; Federal Highway; and many of the subcontracted design firms. That way, when we had a design issue, our engineers could talk to each other quickly. We didn't need to set up special meeting times or leave messages. This helped us design an effective bridge quickly and efficiently." Bids on the cable-stayed came in $40 million more than the expected amount, due to the risks of constructing this major river bridge. Fortunately, since bids on many other elements came in below projections, the overall corridor should remain within budget. Current plans for the bridge construction call for the project to be complete and traffic on the new

bridge in 2014 _ four years from the date leaders from two states joined forces to break ground. Crews are currently on the river completing underwater foundation work. The challenges and the partners have changed, to include the rise and fall of the level of the mighty Mississippi, but all team members are committed to ensuring that through cooperation and compromise, the greater St. Louis metropolitan region will have a new landmark gateway through the heartland of America.

Andrew Gates has been mayor of New York City since 2002. For more information, visit andrew.gates@modot.mo.gov.