There are scheduled domestic flights 2 - 3 times a day between Accra, Kumasi, Sekondi and Tamale in the north including flights by Antrak Air. There are also filghts to destinations outside the country.
CityLink also flies between Accra and Kumasi, etc. (http://www.flycitylink.com)
Roads are variable. In Accra most are fairly good. Significant improvements are being made on the main road between Accra and Kumasi. Most of the roads outside Accra apart from the major ones are dirt tracks. The road between Techiman and Bole is particularly bad and should be avoided if possible. For travel on most roads in the North of the country a 4x4 is required, a saloon car will cope with some of them in the dry season but is not recommended.
Also it should be noted that cars with foreign registration are not allowed to circulate between 6PM and 6AM. Only Ghanaian registered vehicles are allowed on the road at this time. Non compliance can result in fines and the impounding of the vehicle for the night.
A 'Tro-tro' is a term that covers almost any sort of vehicle that has been adapted to fit in as many people, possessions, and occasionally livestock, as possible. Tro-tros are typically old, 12-passenger VW or Mercedes-Benz vans. Similarly to 'shared' taxis, tro-tros will run along fixed routes and have fixed fares, and will rarely run with less than capacity [so be prepared to wait]. They are inexpensive cheaper than shared taxis and STC buses and fares should reflect distance traveled, however they have a questionable safety record and frequently breakdown. Breakdowns however are usually not too much of a problem since they will break down in a route where other tro-tro's run, so you can just grab another one. Although they generally run point to point they will usually pick and drop on route if required. They make runs within the city i.e. Circle to Osu for GHâµ.20 as well as intercity routes. They are often the only option between remote towns but are not recommended for long journeys. Tro-tros are an excellent way to meet Ghanaians, and are always great for a cultural adventure. Sometimes they will make you pay extra for luggage, and occasionally they will try to overcharge very rarely.
If you feel like being an elite tro-tro rider, ask around for City Express, a newish service sporting the usual minivan, but with working breaks, non-stop travel, half the seats, and impressive air conditioning. It mostly runs between the larger cities along the coast, e.g., Takoradi, Accra, Aflao, et al.
STC is the main coach company. They operate long distance domestic and international services. Probably the safest way to travel long distance, and are also pretty quick compared to other options, although even on these services breakdowns are reasonably frequent. STC operate between Accra, Kumasi, Takoradi, Tamale, Cape Coast and other main cities. 'Express' or 'Air-conditioned' services are quicker and a lot more comfortable than the ordinary services and are now available on the Accra-Kumasi, Accra-Tamale, Accra-Bolgatanga routes. Buy your tickets a day in advance though, often times they will be full if you wait until the day of travel. Also, expect to pay for your luggage based upon its weight. It should rarely be over 1/3 the price of the ticket.
Several other companies also operate bus services between the major towns, these include OSA, Metrobus and Kingdom Travel, their service is marginally more reliable than tro-tros but there isn't much in it. Metrobus is by far the cheapest and best option going between Accra, Kumasi and Cape Coast but not recommended for tamale due to the hassle of obtaining a ticket amongst the massive crowds seeking this destination.
The VIP bus company is now the major carrier between Accra, Kumasi, etc. Its 25ghc each way in new a/c Yutong coaches ,6 hrs with a meal stop at the excellent 'Linda Dor'. No advance tickets ,turn up and go,every 15 to 30 mins departures.