While the official airport taxis at $12 are legitimately regulated, you can save even more by taking Bus Line 03 from Psar Thmei (Central Market) to Siem Reap International Airport for literally 1500 riel ($0.37). These clean, air-conditioned buses run every 15 minutes during peak hours, every 30 minutes off-peak, from 5:30am to 9:30pm daily.

Catch it at the official bus stop on the north side of Central Market near Wat Phnom, or at any of the designated stops along Monivong Boulevard. The 45-minute journey takes the scenic route through downtown Phnom Penh, past the Royal Palace, along the riverfront, and through local neighborhoods - basically a free city tour instead of staring at a taxi ceiling.

Pro tip: Board early if you have luggage since overhead space fills up fast. The route map is posted at every stop, and conductors announce major landmarks in English. Perfect if you're not rushing to catch a flight and want to save that $11+ taxi money for actual amok or beef lok lak instead of airport food.

During 4-6pm rush hour, factor in up to 60 minutes travel time due to traffic around Toul Kork and Russian Boulevard intersections. But honestly, watching real Phnom Penh life through those big windows beats sitting in traffic in a stuffy taxi any day.