Complex sentence: By law, passengers may only travel on Amtrak's network of thruway motorcoaches when connecting to or from an Amtrak train, to prevent government-subsidized competition with Greyhound Bus Lines and other private bus companies.
Split into simpler sentences: By law, passengers may only travel on Amtrak's network of thruway motorcoaches when connecting to or from an Amtrak train. The reason for this is to prevent government-subsidized competition with Greyhound Bus Lines and other private bus companies.