Commuters along the Route 355 corridor in Bethesda may notice the start today of the two-week closing of Elmhirst Drive, north of the Walter Reed National Military Medical Center.

This is WSSC water line work that foreshadows some of the roadway reconstruction to ease traffic congestion around the medical center. The water line work, followed by sewer line and gas line relocation, should not affect traffic along Rockville Pike/Wisconsin Avenue in that area.

But some other relocations involving communications lines may have an impact at off-peak hours. As yet, there’s no schedule of lane closings for the project, but we’ll share any of that with you as the project develops.

The lane closings probably will begin at the start of April.

The Maryland State Highway Administration project, developed as planning was underway to transfer military employees and patients from the Army medical center on Georgia Avenue, will include several work zones.

Along Route 355 to the south of the Bethesda medical center, work getting underway this spring will convert a southbound through lane to a second left-turn lane onto Jones Bridge Road. The new one would be available for turns only during the afternoon peak.

SHA will also widen the outside of the southbound roadway in front of the National Institutes of Health, on the west side of Route 355.

To the east of the medical center at Connecticut Avenue (Route 185), SHA will begin work at the Jones Bridge Road intersection. This also will start with utility relocations, but they are relatively minor.

The benefit to commuters will be the addition of a right turn lane along southbound Connecticut between the Capital Beltway and Jones Bridge Road and a new through lane on northbound Connecticut from an area north of Manor Road up to the Beltway. That should be done in the summer or fall of 2013.

Connecticut Avenue and Rockville Pike are major commuter routes for D.C. as well as for the medical center and NIH, and the traffic congestion is intense at peak periods. The commuters and the neighborhoods have been worried for years about the military relocations.

But it takes a long time for transportation plans to catch up with the base realignment programs. So far, travelers are mostly aware of some sidewalk projects and a new traffic signal at the medical center’s Wood Road entrance.

In addition to the SHA projects, we also should see construction starting this year on a pedestrian tunnel at the Medical Center Metro station. This will allow commuters to walk under Rockville Pike to get between the station and the medical center.