Transportation in Indianapolis consists of a complex network that includes a local public bus system, several private intercity bus providers, Amtrak passenger rail service, four freight rail lines, an Interstate Highway System, two airports, a heliport, bikeshare system, 115 miles (185 km) of bike lanes, and 116 miles (187 km) of trails and greenways. The city has also become known for its prevalence of electric scooters.