Today, China is linked by an evolving network of roads (China National Highways) and expressways (Expressways of China). In the past few years, China has been rapidly developing its highway system. Between 1990 and 2003, the total length of urban roads in China more than doubled; increasing from 95,000 to 208,000 kilometers of roads during that period. Similarly, during the same period of time, the total area allocated to roads more than tripled; from 892 million square meters in 1990, to 3,156.5 million square meters in 2003.[8] China National Highways stretch to all four corners of mainland China. Expressways reach the same destinations as China National Highways, except for the rugged terrain of Tibet. An expressway link is already at the planning stage.