The annual Memorial Day weekend ride by Rolling Thunder is in the works.
The bikers will be seen around town with special events beginning Friday.
The weekend culminates with a ride and demonstration Sunday at the Vietnam Veterans Memorial.
Rolling Thunder is a non-profit group publicizing prisoner of war and troop missing in action issues.
The Park Service says drivers should expect delays and road closures throughout the day around the Mall and monuments.
Officials said public transportation is the best way to get around.
Among the closures, Constitution Avenue from Pennsylvania Avenue Northwest to 23rd Street Northwest, and Independence Avenue from 1st Street Southwest to 23rd Street Southwest.
Memorial Bridge and Memorial Avenue will also be closed from Route 110 to Arlington Memorial Circle. Ohio Drive will be closed from Independence Avenue to Virginia Avenue.