Commuters will have to wait at least another year for a smooth ride up and down Morrissey Boulevard now that construction has begun on two bridge restoration projects just as work is coming to an end on a massive drainage overhaul project that has disrupted northbound traffic for several years.

The Lech Walesa Bridge, the overpass that raises Morrissey Blvd. over Mt. Vernon St. by the JFK/UMass MBTA station and leads into Kosciuscko Circle, needs a complete reconstruction to bring it up to today’s standards. The quarter-century-old structure, named for Nobel Peace Prize winner and former Polish President Lech Walesa, is a pre-cast concrete box beam bridge that measures 94 feet long and supports two lanes of traffic and leads into Kosciuszko Circle where the boulevard meets Columbia Rd.

During most of the 14 months planned for construction work, traffic on the bridge will be limited to a single lane in both directions.

A state presentation given to the community at Boston College High in July noted that the north end of the bridge has shifted approximately three inches over the years. Inspections have determined that the bridge is in poor condition and “structurally deficient.” The new superstructure will feature a concrete deck with steel beams designed for a 75-year service life. The substructure of the bridge will be retained, abutment walls will be repainted, and new under-bridge lighting will be installed, according to the plan.

A few hundred yards south along the boulevard sits the Bonetti Memorial Bridge, which separates Savin Hill Cove on the east from Patten’s Cove on the west, At 26 feet wide, it is larger than the Mt. Vernon Streert overpass, spanning three lanes and eleven-foot sidewalks each way. Built, like the Walesa Bridge, in 1984, the bridge’s precast concrete deck beam construction was found to be in fair condition by inspectors who also cited joint deterioration and pavement cracking. The bridge is named in honor of Anthony J. Bonetti, who died in World War II.

Plans for the Patten’s Cove bridge renovation call for a new galvanized steel superstructure with jacked arches and a repaved surface. All three lanes will remain open to traffic throughout construction. As part of this project, new median fencing will be erected along the boulevard in front of The Boston Globe to the west and B.C. High to the east.

Funds to renovate the bridges come from $3 billion appropriated in May of last year as Governor Deval Patrick’s Accelerated Bridge Program. The money is being used throughout Massachusetts to revamp the state’s collection of outdated crossings.

The neighborhood’s other main thoroughfare, Dorchester Ave., is set for a major overhaul that could begin this year. Federal funding from the American Recovery and Reinvestment Act has accelerated the timetable for the long awaited project. Fifteen intersections will be redone, from the Ashmont MBTA station to Andrew Square in South Boston.