The D.C. Circulator bus system is expected to expand with at least two new routes in 2008, one between the Walter E. Washington Convention Center and Adams Morgan, and the other from Union Station to the new Washington Nationals ballpark.

The two-year-old, increasingly popular Circulator buses currently operate on three loops, one around the National Mall, one between Union Station and Georgetown, and a third between Mount Vernon Square and the Southwest waterfront. Each ride costs $1.