ALLENTOWN, Pa. -

Rehabilitation of Allentown's  8th Street Bridge -- officially called the Albertus L. Meyers Bridge --is expected to begin May 5.

The 100-year-old bridge, which links center city with south Allentown, will be closed to southbound traffic during the $18.5-million project, which is scheduled for completion in 2016.

Only one northbound lane will remain open for traffic heading into downtown.

Southbound traffic will be detoured to Union and Lehigh streets.

To accommodate the detour, the city temporarily will implement a two-way traffic pattern on Union Street between Seventh and Eighth streets for the duration of the project.

That section of Union Street currently is one-way westbound.

One of the two sidewalks on the bridge will remain open to pedestrians during construction.

The bridge spans Little Lehigh Creek, Norfolk Southern Rail Road, Harrison Street, Martin Luther King, Jr. Boulevard and Fountain Park in the city.

The work schedule, which could change, was announced Friday by the Pennsylvania Department of Transportation.

IEW Construction Group, Inc. of Trenton, N.J., is the general contractor on the $18,541,535.84 project.

Work will include replacing the bridge deck, constructing new alcoves, repairing bridge piers, reconstructing  roadway approaches, installing new ornamental lighting, concrete curbing, concrete sidewalk, protective fencing, pavement markings and signs.

The Eighth Street Bridge was originally constructed in 1913 and last rehabilitated in 1973. Trolleys once ran across the bridge and motorists had to pay a toll to cross it.

It is a 17-span, concrete open spandrel arch bridge with nine main spans and eight reinforced concrete T-beam approach spans.

It is 1,959 feet long and 46 feet wide and has an average daily traffic volume of 16,950 vehicles.