Camair-Co operates as a national carrier and on domestic flights.
Rail services operated by Camrail, run from the capital, Yaoundé, to the port city of Douala and the northern city of Ngaoundéré. While bus service is quicker and more reliable to Douala, the overnight train is the best mode of ground transport to the north. Check for current schedules and pricing.
Between the major cities you can get a ride on modern, comfortable buses, sometimes with air conditioning. Away from the larger centres you will most likely end up on the ever present Toyota bush taxis. These are slightly elongated Toyota minivans that can hold up to 20 people (or more if necessary) along with their luggage piled up on top. Safety can be a concern with dangerous roads, overworked/drunk/hungover drivers and poorly maintained vehicles the norm. However, other than extending your stay an extra day or two in bad weather your options are limited.
Buses rarely leave at a set time. Instead, they wait until they are full and then depart. For buses later in the day, sometimes they never fill up. When this happens, the operator will normally set you up with a bush taxi to take you to your destination. If you do not want to take the bush taxi and are persistent enough, the operator will normally refund your money. The point is that you should leave plenty of time to get to your destination, because sometimes the wait will take hours and you are never guaranteed a departure.
Rental cars are available although very expensive. As paved roads are rare away from the major cities of the west and northwest areas of the country, a 4 x 4 is a necessity when travelling to the east or central areas of Cameroon. The roads in the north are paved between cities and even the dirt roads tend to be in decent condition due to the lack of rain.
You can hire a private car and have its driver take you to places of your choice. Expect to pay around USD60 per day to the driver and foot the gas bill. The driver will also expect you to provide food and accommodation. But you can bargain.
These days, due to bad roads and congestion, motorcycles are a common form of transportation. The driver can take you wherever you want and they can be the only alternative to remote villages that do not have paved roads.