LANHAM, Md. (CBSDC) — Shortly after Thursday morning’s rush hour, the westbound lanes of the Southeast Freeway will close between Pennsylvania Avenue and 8th Street, SE in the District.

The closures are part second phase of the ongoing 11th Street Bridge Project, aimed at improving traffic flow around Capitol Hill.

Drivers will be detoured onto I-695, which will lead back to freeway, during the closure.

The District Department of Transportation estimates the lanes will remain closed for approximately 18 to 20 months, meaning the detours will be in place until mid-2014.

Also Thursday, DDOT will open the recently completed ramp from 11th Street, SE to westbound Southeast/Southwest freeway.