METRO began running light rail service (METRORail) on January 1, 2004. Currently, the track is rather short — about 22.7 miles (20.6 km) from Northline Transit Center Station through downtown Houston to the Texas Medical Center and Reliant Park, and lines from downtown to the East End and the University of Houston/Lower 3rd Ward. Still, the system is traveled by about 61,000 people daily, giving it the second-highest ridership per track mile in the nation. The Uptown Light Rail Line has been converted to a BRT Line and began construction in the late 2nd quarter of 2016. The BRT Line will run between the former NW Mall (which is in the process of redevelopment) and the WestPark TC. METRO's various forms of public transportation still do not connect multiple suburbs to the inner city (defined by the 610 loop), causing Houstonians to rely on the automobile as a primary source of transportation. The problem is one due to the lack of a central metropolitan area transportation authority, primarily due to a few suburban counties refusing to cooperate with METRO. For example, there are multiple coach bus services that run into downtown Houston. METRO is in the late planning stages of the US 90 Commuter line which will service the Ft Bend County and SW Harris County suburban region. Prior to the opening of METRORail, Houston was the largest major city in the United States without a rail transit system.