(Walnut, Beechurst, Engineering, Towers, Medical) along a route. All stations are on sidings, which allows vehicles to bypass stations. It takes 11.5 minutes to ride the entire length of the system from the Walnut Station to the Medical Station. The guideway consists of concrete pathways with magnetic induction loops that provide car location data. The system's concrete pathways have embedded pipes that circulate a glycol solution, which is heated at stations to help melt snow and ice prevalent in Morgantown's snowy winter climate. Most of the system (65%) is built on elevated bridges and viaducts, while the remainder is at or below ground level. The viaduct spans are approximately long, and there are two styles of viaduct, with those constructed in Phase I being noticeably heavier-duty than those built in Phase II. Modes of operation The system is fully automated and can operate in three modes: "demand", "schedule", and "circulation". Demand: When used during peak hours, the system reacts dynamically to rider requests, comparable to utilizing an elevator. At the fare gate, after the rider pays the fare, they will press the button associated with a particular destination to call a car. This will start a timer within the system. If the timer reaches a predetermined limit, typically 5 minutes, a vehicle is activated to service the request even if no other passengers have requested the same destination. Also, if the number of passengers waiting to travel to the same destination exceeds a predetermined limit, usually 15, a vehicle is immediately activated. User will look at the electronic signboard above the boarding gate to determine which car to board. Once the car arrived, the doors remain open for 20 seconds for boarding, before the vehicle departs to its destination, avoiding any intermediate stations. In this mode the system operates as a true PRT. Schedule: System switch to this mode during periods with well-known travel-demand patterns, and operates the cars on fixed routes of known demand. This lowers the waiting time for a car traveling to a given destination and is more efficient than demand mode. Circulation: System switches to this mode during off-peak hours, operating a small number of vehicles that stop at every station, like a bus service. This reduces the number of vehicles traveling on the network, but increase travel time to destination. Performance In the 2006 fiscal year, the system broke down 259 times for a total