Cambodia has a network of buses that connects major towns, including Phnom Penh, Siem Reap, and Sihanoukville. Buses can range from unsafe to more comfortable, with air conditioning and WiFi. The fare for public buses is 1,500 riels (USD 0.37) per voyage, and you pay each time you get on and off a bus. Only local currency Riel is accepted. However, senior citizens (age over 70), small children (under 1 meter), disabled, monks, teachers, students, and factory workers travel free.
Here are some other Cambodia bus transportation services:
Giant Ibis Transport
Angkor Batman - Share Day Tours
Cambodia Transport Service
Why Not Angkor Driver
Mekong Express
Larryta.com
Location
Cty Bus Express And Travel Street 230 Behind National Olympic Stadium Cambodia, Cambodia