The state Department of Transportation (DOT) will be shifting the lanes of traffic flow on the two Interstate-84 bridges which cross above Center Street in the Riverside section of Sandy Hook.

The construction work required to shift the location of traffic flow on the two 100-foot-long bridges is scheduled to start on Sunday, June 2, and continue to Friday, June 21. The parallel bridges lie about 90 feet apart from one another.

The traffic-lane shifts are being done in preparation for the reconstruction of the two bridges, which lie about 1,000 feet west of Lake Zoar. That reconstruction project is expected to take two years to complete.

Traffic flow on the bridges will be shifted laterally through the use of concrete barrier rails on the bridges’ decks.

Each of the two I-84 bridges carries two lanes of traffic. When the traffic-lane shifts on the two bridges are created, two lanes of traffic will continue traveling on the two bridges, with one of those two lanes occupying what are now road shoulders.

The lane shifts on the bridges had been scheduled to start in early April but has experienced delays.

Last August, the DOT awarded Manafort Brothers, Inc, a contract to reconstruct the two I-84 bridges at a cost of $5.9 million.

The I-84 bridges have deteriorated sooner than anticipated and thus need to be replaced. The bridges’ prestressed concrete beams are in poor condition due to cracking. The bridges were built in 1977 and 1978. Bridges typically are designed to last for 75 years of traffic service.

The bridge project would include replacing the bridges’ concrete girders and also the concrete deck slabs.

Because the state right-of-way in the bridge area is approximately 350 feet wide, the state will not need to acquire rights-of-way for the project.

The bridge reconstruction project initially had been scheduled to start in the summer of 2012.