Short distance trains, also known as commuter trains or suburban trains, typically serve a city and its surrounding suburbs and are an efficient answer to the large traffic demand in cities. Commuters trains, are important mode of transport to those traveling to and from their work place. Their history can be traced back to the 19th century when trains were the only mode of transport. Short distance trains can travel longer ranges in comparison to rapid transit with speeds from 30 to 140 miles per hour. Characteristics of commuter trains include being larger, multiple seating arrangements, less standing room, lower frequency of service, scheduled service times, service to lower-density areas, sharing tracks with freight trains, not fully grade separated, and express services.