The small span crossing Good Harbor Beach Creek in Gloucester was built in the 1920s, at a time when men favored felt fedoras, young couples were swept up in the Charleston dance craze, and Henry Ford was peddling his Model T.

The little bridge may have survived the bygone classics of its era, but the ravages of time are taking their toll. Heavy truck traffic and harsh New England winters have left an indelible imprint. Large chunks of concrete are missing. Portions of the span's hulking steel frame are exposed and rusting. And the beams that support the 37-foot structure are cracked and in need of replacement.

The Good Harbor Beach Creek Bridge illustrates the travails of repairing and replacing bridges in Massachusetts, which is home to some of the oldest bridges in the nation. About one in eight bridges -- approximately 560 of the 4,400 bridges that the state Highway Department inspects and maintains -- is listed on a federal database released last year as ''structurally deficient."

''A lot of our bridges were built right in the early days of bridge building, in the 1930s," said Alexander Bardow, state director of bridges and structures. ''At that time, they didn't waste any inches. They built bridges only as wide as they had to be. A lot of those bridges don't meet today's standards for lane width."

More than half of the Commonwealth's 4,900 bridges are more than 40 years old. Many of those, however, could be called baby boomer bridges -- built in the first decade after President Dwight D. Eisenhower signed the 1956 federal highway funding bill into law.

In all, 1,857 Massachusetts bridges were built in the 1950s and 1960s, state records show. The fevered pitch of construction during those decades represented the largest bridge boom since the 1930s, when 612 spans were erected in the Bay State, according to a report released in November by the Massachusetts Infrastructure Investment Coalition, which based its findings on MassHighway inspection figures.

Among the area's communities, 16 -- Amesbury, Beverly, Chelsea, Danvers, Gloucester, Groveland, Hamilton, Haverhill, Lynn, Newbury, Newburyport, Peabody, Revere, Salem, Saugus, and Topsfield -- have at least one bridge considered to be structurally deficient.

Overall, about 17 percent, or 55, of the area's 332 bridges are structurally deficient, according to the June 2005 federal database. Danvers leads the region, with 11 structurally deficient bridges, followed by Amesbury and Haverhill, each with seven.

The designation does not mean that the bridges are dangerous. Rather, it means the spans have problems that need to be corrected.

The state spent roughly $206 million to repair and replace bridges last year, up from $188 million in 2004. Despite the swell in funding, MassHighway -- the agency charged with overseeing the projects -- can hardly keep pace with demand.

In Gloucester, city leaders have been calling for action on the Good Harbor Beach Creek Bridge for nearly a decade. Finally, this fall, the dilapidated bridge on Thatcher Road is expected to join other symbols of its time and fade into memory.

The cost of construction: $1.7 million.

''It's a vital estuary, a link between Rockport and Gloucester and Good Harbor Beach," said Gloucester Mayor John Bell, noting that more than 13,000 motorists cross the span daily. ''I can't say why it's taken so long to get to this point. I guess it's true what they say -- good things come to those who wait."

Officials and engineers are quick to point out that every bridge involves unique engineering and construction demands, and that permits are often difficult to secure. In many cases, neighbors' concerns about the prospect of flooded basements or lengthy detours also can delay construction. In addition, utility lines may have to be moved or ownership issues resolved, a process that can put a project on hold for months.

Because of such factors, what might appear a relatively easy undertaking -- erecting a span over a stretch of water or roadway -- can be complex, time-consuming, and costly.

''There's never enough money to do all of the work that is out there," said Danvers Town Manager Wayne P. Marquis, who has been pushing state officials to repair the town's Water Street bridge for the better part of five years. Work on the span, a granite block structure, is expected to begin this year. The timeline depends in part on the relocation of several utility lines, including a Salem water main.

''It's not that the state hasn't felt that these projects are important," Marquis said of the delay in getting bridge projects in Danvers off the ground. ''Rather, it was a question of priorities."

Throughout the region, MassHighway is proceeding with plans to repair or replace decrepit bridges. In addition to the Good Harbor Beach Creek project, the agency is replacing two bridges in Peabody. One of the spans crosses Lowell Street (cost: $2.7 million). The second is a wooden pedestrian bridge that crosses the MBTA tracks ($975,000). Both projects are scheduled for completion this year.

In Newbury, two projects are in the works. The first will replace a Hay Street bridge that connects routes 1 and 1A. The $1.1 million project, which is expected to begin this spring, will take two construction seasons to complete, according to Erik Abell, a spokesman for MassHighway.

The second Newbury project -- the $6.9 million reconstruction of the Route 1A bridge over the Parker River -- awaits a permit from the Coast Guard. In the meantime, state officials have affixed large black nets to the underside of the bridge in an attempt to keep falling concrete and debris from hitting boats and the structure's deteriorating pillars.

In Revere, MassHighway plans to replace the aging Revere Street bridge, a heavily traveled span that leads to an elementary school and the MBTA's Wonderland Station ($3.7million).

''We're going to continue to work with the resources we have, and work to spend more money on our bridge program in order to reduce the number of structurally deficient bridges," said Jonathan Carlisle, spokesman for the state Executive Office of Transportation. He noted that the state employs 34 bridge inspectors who work year-round in two-person teams.

So far this year, the state has pumped more than $17 million into bridge repairs. The money can't come soon enough to cities and towns that have closed bridges, or spans with weight restrictions that ban heavy truck traffic. Statewide, 40 bridges are closed and another 519 have weight restrictions.

Haverhill is dealing with both. The Rocks Village Bridge, which spans the Merrimack River and connects the city to neighboring West Newbury, is showing signs of strain. Built in 1883, its concrete and timber decking needs to be replaced and several of its movable parts must be upgraded. The bridge is in such sorry shape that West Newbury can no longer drive town plows over the structure. Work on the span is expected to begin in the fall of 2007.

Nearby, construction crews are working to replace the Joseph C. Comeau Bridge, which also crosses the Merrimack River. The bridge has been closed since June 2002; workers began to erect the new span the following summer. The work is expected to be completed by Labor Day 2007, according to Abell.

Haverhill residents have developed a sense of humor about the project. A few make jokes about the mating habits of sturgeon; work on the bridge has at times been halted to accommodate the spawning fish. Some business owners refer to the ongoing work as Haverhill's version of Boston's Big Dig, while others say, tongue in cheek, that they have started to see the project as a valuable addition to the landscape.

''When people ask where we're located, we tell them, 'You know that bridge that will never be done? We're across the street from it,' " said Michael Pimentel, branch manager of Enterprise Rent-a-Car's downtown Haverhill office.

''If nothing else, it's a good landmark."

Matt Carroll of the Globe staff and Globe Correspondent Richard Thompson contributed to this report. Brenda J. Buote can be reached at bbuote@globe.com.

NorthTalk

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