Ins and outs
Ban Lung is 13 hours from Phnom Penh. It is better to break your journey in Kratie and Stung Treng and take a pickup/taxi from there. The chief mode of transport is the motorbike, which comes with a driver, or not, as required (usually US$5 without driver and US$15 with, but you’ll have to haggle). Bus services are sporadic. Cars with driver can be hired for US$40-50 a day.
Ban Lung and around
Air
There is an airport in Ban Lung but the old plane that used to fly from Phnom Penh crashed near Bokor, taking several Korean tourists with it. There are no plans at the time of writing to begin flights again.
Bus
There is now a daily bus from Ban Lung to Phnom Penh, 12 hrs, $15.
Motorbike/moto
Several guesthouses have motorbikes for hire, or can arrange hire, for around US$5 per day without driver and triple that with a driver. There are no garages/petrol stops outside the town of Ban Lung, though there are a few roadside places offering bottles of fuel of dubious quality, so it is advisable to set off with a full tank. Lake View Lodge can also arrange moto and dirt bike for US$5-10 per day.
Shared taxi/pickup
If you are a glutton for punishment or just want another after-dinner story when you get home, it is possible to travel directly to Phnom Penh but be prepared to sit in a cramped pickup/taxi for around 13 hrs. Taxi to Kratie, leaving the taxi stand at approximately 0800, 7 hrs, US$12-13; taxi to Stung Treng, 0830, 2-3 hrs, US$5-7.
You can only get a moto to take you to Lumphat for around US$15 for the day trip. The road from Stung Treng is fairly well graded now and is constantly improving due to its use by logging companies. The trip to Ban Lung from Stung Treng takes about 3 hrs (if you get yourself in a nice new Camry), US$10.
Tourists commonly ask about travelling between Ban Lung and Sen Monorom. At the time of publication this overland odyssey really wasn’t an option, as the roads are almost impassable and difficult to navigate. Only experienced dirt bike riders with very good local knowledge should attempt this trip.