In Vietnam, bus is the cheapest and most convenient means of transportation for foreign travellers, since the bus system has been well-developed and covered almost every part of the country. If you are stuck on the very first steps such as how to find a bus or which route to go, stay calm and read the following guide.
Each province in Vietnam has its own major terminal, especially in big cities like Hanoi (My Dinh Bus station, Giap Bat Bus station), Ho Chi Minh City (Mien Tay, Mien Dong); you can find buses going to every tourism destination as well as other province in Vietnam. Typically, interprovincial buses are high quality ones with good services, large and comfortable seats. All you have to do is to buy tickets from registered ticket booths inside the terminal, and later show it to the conductor on the bus. There is no limitation for the size of baggage.
The price depends on the distance of the route and type of seats chosen. Tourists can ask their travel agencies to purchase ticket in advance, or even book ticket via phone or Internet by themselves. Notice that Internet booking bus ticket is not very popular, only applicable to a few large bus companies. If you depart from minor provinces and there is no direct route to your intend destinations, it is advisable to catch a bus to major cities (Hanoi for northern provinces, Hue or Da Nang for central area, and Ho Chi Minh City for southern provinces) and then change the bus there.
In Hanoi, Ho Chi Minh City and some major tourism destinations, there is public bus service for people both local and foreigners. Those buses also departure from major terminals before heading to other streets. In other provinces, we also have buses run by private companies. Passengers can catch bus at bus stops scattering around the province and buy ticket directly from the conductor. Although the ticket is very cheap (under VND 10000), the service is not very high (you may have to stand if the bus is too crowded, or the conductor cannot speak English). However, local bus is one interesting way to understand more or make friends with local people.
The so-called Open buses are privatised long-distance bus services targetting tourists (though also popular with locals) running the length of Vietnam -- commencing at Hanoi the service stops at Hue, Hoi An, Nha Trang, Da Lat and Mui Ne, among others, terminating in Saigon (obviously it runs in the reverse as well). There are spurs off into the Mekong Delta and Tay Ninh in the south (ex-Saigon) and Ha Long Bay and Sapa in the north (ex-Hanoi). They offer door-to-door service and you should book a day ahead.
The ticket price is dependent on where you choose to stop, and once you buy the ticket, you're locked into that route -- unless you buy a new ticket. The cost is very low -- as little as US$35 (the price may change at the book time, please contact us for best prices) for a non-stop epic from Hanoi to Saigon. The Open buses system work for thousands of visitors to Vietnam -- particularly first-time visitors who may be intimidated by the local bus system or who are looking for more creature comforts.