mayoral candidate Rob Richardson Jr. ran unsuccessfully on a platform that included reviving the subway system; however, this did not provide tangible construction plans or feasibility studies. Current status The uncompleted subway tunnels and stations have been described as "in good shape." This is partially credited to the original construction quality, and partially because Cincinnati needs to maintain the tunnel, using tax revenues, due to the presence of Central Parkway on top of it. In 2008 it was estimated that it would cost $2.6 million to simply keep maintaining the tunnels, $19 million to fill the tunnels with dirt, and $100.5 million to revive the tunnels for modern subway use. Relocating the water main would cost $14 million. , the abandoned tunnel is used to carry the relocated water main and some optical fiber cables. The abandoned tunnels are frequented by urban explorers and the homeless. Stations and route Seven stations were completed along Central Parkway: four underground and three above ground. The underground stations remain intact, but the above-ground stations were demolished when I-75 was built in the 1960s. The underground stations' locations are at Race Street, Liberty Street, Linn Street, and Brighton Place, while the above-ground stations' locations were at Marshall Street, Ludlow Avenue, Clifton Avenue, and Reading Road. The first station was the Race Street Station, which was to serve as the main hub. It was configured with the platform in the center, with the subway running along the north and south side. Next was Liberty Street, which was a through-station. It was a simple design with a platform on each side of the track. Third was Linn Street, also a through station. Laid out similarly to Liberty Street, this station has been sealed up, and can be easily missed when walking through. Fourth was Brighton Place, another through-station. Marshall Street was the most grand of the above-ground stations, located to the west near the Mill Creek Valley. Ludlow Avenue Station was constructed under the south side of the Ludlow Viaduct and was also a through-station. The last to be completed was Clifton Avenue, which was located where the street passes under present day I-75. There were additional stations in the plan; however, funding ran out as the project reached Norwood. Engineering The subway tunnels run north and south. Each of the two halves of the tube has a minimum width of and a height of .