When the first of the Asian adventure travelers first discovered the Kingdom of Cambodia using the term roads was merely an easy way for saying improved tracks of endless quagmire in the rainy season, and axel snapping, oil pan crushing track for the rest of the year.
Voted 10 years in a row the worst road in the world, the path between Bangkok and the Temples of Angkor Wat today carries large 48 seat buses under passable conditions for the better part of the way, but then the back wrenching, pitching, lurching and stomach emptying for many begins and continues for 100 kilometers to the Thai border, where you will find and really appreciate, western standard roads for the rest of the trip.
Going into the provinces of Cambodia is now possible with many options including share taxis and mini buses. The main routes between Phnom Penh & Siem Reap and Phnom Penh to Sihanoukville you can now find buses that would be rated first class in Thailand, with the definition of first class being air con with a small water closet. Some of the legacy carriers will assault you with Khmer karaoke classics at painful volume; Mekong Express being the exception which shows previews of the temples, and on the other routes you will be able to keep up to date with all of the Mr. Been adventures, which like chocolates, has everyone smiling regardless of where on the blue marble they come from.
Dining can be a real culinary adventure on most of the routes, expect to be wined and dined with mongrel flea ridden dogs, lactating cats and bugs that go whir in the night, sometimes they are begging for your food, other times they are featured on your plate! The fare using the term in its loses meaning, is mostly passed over by all but the most hardy of travelers unless of course you are partial to things like chicken embryo’s and 1000 year old eggs. You need to do your shopping before you go to the bus stations as the choices are very limited if you want western snacks. They sometimes will have fresh fruit for sale, pineapple and bananas being found most often. The soft drinks they offer are Cokes and beer and all sorts of Asian drinks that you probably not familiar with like green jelly or soy milk soda. The coffee and tea that they have is generally horrible tasting which is a kind understatement unfortunately.
The fares are very comparable to distances in Thailand or Vietnam for the cheap buses. You can get from Phnom Penh to Sihanoukville for $6, Phnom Penh to Siem Reap under $10, and to Bangkok or Saigon for right around $20 give or take from most parts of Cambodia.