This is a list of autopistas, or tolled (cuota) highways, in Mexico. Tolled roads are often built as bypasses, to cross major bridges, and to provide direct intercity connections. Many federal highways corridors numbers cover more than one autopista; other federal highways do not have limited access sections. Normally, Mexican federal highways that are on toll roads have the letter suffix "D" for Directo, e.g. Fed. 45 is free (libre) and Fed. 45D is toll (cuota). Most autopistas have a toll over all or part of their length. A few autopistas in very mountainous areas are two-lane.