Train surfing

riding on the exteriors of rail vehicles

thumb|upright|Freight-hopping youth near Bakersfield, California ([[National Youth Administration, 1940)]] Freighthopping or trainhopping is the act of boarding and riding a freightcar without permission. This activity itself is often considered to be illegal, although this varies by jurisdiction. It may be associated with other illegal activities such as theft, vagrancy, or trespassing.

Mexican freight trains used by migrants