Bus: Your best bet if you don’t have your own transportation is to take the Hoh Wah renting bus. To and from Phnom Penh costs just 5,000 riel on the air-con bus.
Kampong Chhnang to Phnom Penh:
departs 6:30 am, 9:30 am, 11:00 am, 12:00 pm, 1:15 pm, 2:00 pm, 3:30 pm, 4:30 pm.
Phnom Penh to Kampong Chhnang departs (from Central Market Terminal) 6:40 am, 8:00 am, 9:00 am, 10:00 am, 11:30 am, 1:00 pm, 2:00 pm, 3:30 pm, and 4:30 pm. If you like, you can get off at Udong and see the old ruins and its newest additions (just grab a moto-taxi next to the entrance road), then go back out to the highway and grab the next bus heading your way to Kampong Chhnang.
It’s about a 1-1⁄2 hour ride up from Phnom Penh. The share taxi costs around US$3.5 from Phnom Penh and it doubles for Pursat.
Highway No 5 from Kampong Chhnang to Pursat is slowly getting some resurfacing work and while not good by any stretch of the imagination, it’s not as bad as it used to be. As mentioned, the Kampong Chhnang to Phnom Penh stretch qualifies a dream road in Cambodia. Security is not a problem.
The bullet boats to and from Siem Reap and Phnom Penh are taking you through a breathtaking countryside along the Tonle Sap to the provincial town. Going from Phnom Penh to Kampong Chhnang you’ll have to find the docking station of the boats, which is just around 200m after the Japanese Bridge to the left riverbank of the Tonle Sap. The price for one trip is around US$8. The price from Siem Reap might get a bit higher as you’re starting from the touristy hotspot. The trip from PP will take approx. 3 1/2h; from Siem Reap approx. 4h (depending on rainy and wet season).