With the closing of westbound lanes on the Southeast Freeway, drivers should continue south to the 11th Street Bridge. (DDOT map)

[This post has been updated.]

An important change in D.C. freeway traffic patterns took place Thursday morning, affecting commuters who use Pennsylvania Avenue to cross the Anacostia River and then pick up the Southeast-Southwest Freeway.

The District Department of Transportation closed the westbound Southeast Freeway between Pennsylvania Avenue and Eighth Street SE. This segment will stay closed for 18 to 20 months while workers raise the roadway and convert it into a boulevard, more connected with the neighborhood than the sunken freeway is.

Commuters affected by the closing should use D.C. 295 South to reach the inbound freeway span of the 11th Street Bridge. That will lead them to the Southeast-Southwest Freeway and I-395.

Around the beginning of the new year, the eastbound lanes in the work zone also will be closed for the boulevard construction.

Meanwhile, a new ramp connecting 11th Street SE with the westbound Southeast-Southwest Freeway is opening Thursday. Drivers on Capitol Hill can use this for easier access from local streets onto the freeway. It will also provide more direct access to the freeway for Anacostia residents who use the local span of the 11th Street Bridge. And it should help the traffic leaving the Navy Yard in the evening.