Ontario International Airport (ONT) is a full-size international airport with direct service to most US hubs, several Mexican destinations, and a handful of Asian cities — for many Inland Empire and Orange County travellers it is a much easier alternative to LAX, 50 freeway miles to the west.
By car, Ontario sits at the junction of I-10 and I-15 — practically every drive between LA and Las Vegas, or between LA and Phoenix, passes through. Traffic on I-10 westbound at rush hour is famously bad. Amtrak's Sunset Limited stops here twice a week from New Orleans and Los Angeles. Metrolink commuter trains run from LA Union Station to Rancho Cucamonga, two stops north.