The cheapest way to get to Pasadena from LAX is to take the Flyaway shuttle and Metro A Line (light rail, formerly known as the Gold Line) combination. It takes ~80 min and costs $11.25 each way.

From your arrival gate at LAX, follow signs to "Ground Transportation", to an outdoor waiting area. Look for the Flyaway sign with posted schedule (see pictures at right). Note there has been a recent re-structuring at LAX and the Flyaway (and all other shuttles) now pick up passengers on the inner curb.

The Flyaway Shuttle to Union Station comes every 20-30 min. depending on time of day (detailed schedule available here). Make sure you get the bus to "Union Station". The Flyaway takes the freeway carpool lane to Union Station, nonstop, duration 25-40 min. Tickets can be purchased ahead of time online. Otherwise, you pay for your ticket when you arrive at Union station. Note they only accept credit cards as payment.

Walk down the bus plaza and into Union Station. Follow "A line" signs. Use the automated teller to buy a TAP card and fill it with at least $3 ($1.50 each way). Alternatively, if you have an iPhone, you can add a TAP card to your Apple Wallet. Tap your card/phone on the green circle at the entrance gate to deduct the fare. There is no paper ticket. Take the Northbound A Line train, which should be signed for Pamona. You'll be on the train for 22 min. Get off at Lake Station. Climb the stairs, and walk uphill on Lake St. Take a left onto Santa Barbara St., walk 50 yards, and you're at our front door. Alternatively, walk to your hotel from Lake Station.

The Metro A line serves Pasadena until ~1 am, with trains every ~15 min (10 min in commuter hours.) Here are links for the A Line map and schedule.

Banner image credit:  Frederick Dennstedt from los angeles, USA, CC BY-SA 2.0