Rail transport in Puerto Rico currently consists of a 10.7-mile (17.2 km) passenger metro system in the island's metropolitan area of San Juan. Its history can be traced back to the mid-19th century with the construction of a limited passenger line in Mayagüez. Between the late 19th and early 20th centuries, Puerto Rico's rail transport system expanded significantly, becoming one of the largest rail systems in the Caribbean at the time thanks to an economic boom in agriculture industries, especially the sugar cane industry. The rail system was expanded to include passenger travel with a direct line from the island's northern capital of San Juan to the western and southern cities and towns, greatly improving travel and communication within the island. However, the entire system was soon overshadowed by the arrival of the automobile, and by the 1950s was completely abandoned. Small remnants of this system still exist in some parts of Puerto Rico, some conserved for tourism purposes.