Recent inspections have found "advanced deterioration" of the pier foundations of the Maryland Transportation Authority's two bridges over the Susquehanna River on Interstate 95 and U.S. 40 - forcing the agency to put repairs to the supporting structures on a fast track.
Dennis Simpson, the authority's capital planning director, said the deterioration poses no immediate danger. "It's safe. We need to do the work to keep it safe," he said. "If it was a situation where the bridge couldn't stay open, we would have closed the bridge. We do need to correct it."
The two projects, expected to cost a combined $53 million, are an indicator of the mounting cost of maintaining Maryland's critical infrastructure at a time when many structures are showing signs of advanced age. The toll authority's recently released draft six-year budget plan - totaling $3.5 billion - includes several expensive projects to address long-overdue maintenance on the bridges under its control - including the Bay Bridge.
The mounting number of rehabilitation projects - and the increasing costs of undertaking them - are putting pressure on the authority's budget at a time when toll revenues have fallen as a result of recession-related traffic declines. Teri Moss, a spokeswoman for the authority, said the growing list of urgent projects is forcing the agency to reconsider its current toll levels.
"We're constantly evaluating, so we might be looking at a potential toll increase in the next couple of years," she said. The authority's basic toll levels have remained unchanged since 2003 except for an increase imposed on trucks and other multi-axle vehicles earlier this year.
Unlike most of the other bridge projects in the budget plan, the repairs to the Susquehanna bridges involve the foundations that support the surfaces upon which motorists drive. For now, the rehabilitation of the piers of the Millard E. Tydings Memorial Bridge on I-95 and the Thomas J. Hatem Memorial Bridge on U.S. 40 is in an engineering stage that is expected to continue through the middle of 2011. The construction phase will follow over the next two years.
Inspections of both bridges turned up deterioration of the foundation upon which sit the pillars that hold up the bridge deck, or driving surface. The authority also found that "scour" from the flow of the river has eroded the pillars themselves.
For authority officials, the inspection results came as a nasty surprise - revealing a level of deterioration that had not been in its long-range plans. In effect, work on the two bridges has been pushed to the front of the line as other work has been deferred.
"This is pretty much the fastest schedule" on which the work can be performed, Simpson said.
The Hatem Bridge is the oldest state-run toll facility in Maryland, having opened in August 1940 as the Susquehanna River bridge - replacing an obsolete double-decker structure. It carries an estimated 11 million vehicles a year and is currently in the middle of a $35 million project to replace a deteriorated deck that was last replaced in 1982. The bridge is also scheduled to undergo a $10 million cleaning and repainting between now and 2012 "to extend the useful life of the bridge."
The Tydings Bridge - named after a longtime U.S. senator from Maryland - opened in 1963 as part of what was later named the John F. Kennedy Memorial Highway, the toll portion of I-95 northeast of Baltimore. While not a toll bridge itself, the northbound bridge feeds directly into the highway toll plaza. Originally a four-lane bridge, it was converted to six lanes in 1972. It carries an estimated 29 million vehicles a year, including a large percentage of heavy trucks.
While the Susquehanna River bridge projects are the only ones in the authority's portfolio that are known to need foundation work, the agency has an expensive to-do list for maintenance to the other spans it manages. The list includes:
* The westbound span of the Bay Bridge, which is midway through a $132 million replacement of its deck, is scheduled to undergo its first complete repainting since it opened in 1973. Engineering on the project has begun and the repainting, which will help extend the useful life of the bridge, is expected to begin by next year. So far, the authority is not aware of any deterioration of the underwater structure of the bay crossings but Simpson said it has allocated $2 million to study whether any such damage is present.
* The Canton Viaduct, the elevated stretch of I-95 between the north portal of the Harbor Tunnel and Holabird Avenue, is scheduled for a full replacement. The bridge deck has not been renovated since 1985 and is approaching the end of its useful life. The superstructure is showing signs of deterioration and the bridge is rated "structurally deficient." Nevertheless, the $165 million construction project has been delayed until 2013 as it has been expanded from a resurfacing to full replacement of the viaduct.