Prior to the civil war many travellers undertook the trip in their own 4x4s or using their own dirt bikes and campervans. It would seem that they encountered considerable hospitality once in the country. Up until the uprisings of 2011 it was not uncommon to see SUVs with Texas plates on them in Tripoli most likely US oil workers of which approx 5-10,000 previously resided in Libya. It was not uncommon to see convoys of European campervans on Libya's highways prior to the civil war. Please make serious and detailed enquires prior to undertaking any trip by road into Libya to determine if the area you will be travelling through is safe and if fuel and other services are available. Travel such as this is not recommended at this time.
Some self-drive car rental services were previously available in the large cities but the rates were typically high and the cars unreliable. Avis and Europcar will no doubt re-commence operations as soon as civil order is restored, they will no doubt be needing to replace their previous fleets. Around the major cities, driving can be an "education".
The recommended route of transport for tourists around major towns is taxis. There are also many shared taxis and buses. The small black and white taxis or death pandas tend to be safer more cautious drivers but learn the term "Shweyah-Shweyah", Libyan for slow-down, and ask them to keep off Al-Sareyah the motorway from Souq-Al-Thataltha to Janzour! A taxi driver will routinely try it on with tourists. Will always try to charge 10 dinars for a fare around town. Negotiate the price first: Prior to the civil war rates around most of inner Tripoli, you should not pay more than 5 dinars. If you find a good taxi driver with a good car, it doesn't hurt to build up a relationship and get his mobile number. Taxis from the airport can be more expensive as the airport is a long way from town. Note that the Corinthia Hotel also runs a shuttle from the airport to the hotel.
There were previously many bus services between the major cities and it was a potentially a cheap way to travel. The bus companies used modern and relatively comfortable air conditioned touring buses however many of the fleets were seriously damaged during the civil war. Longer journeys such as Tripoli to Benghazi will take about 14 hr by bus. The buses make stops for meals and the very important tea shahee breaks along the way. A faster method is to take the "shared taxis" but some of the drivers tend to be more reckless in order to cut the travel time. Services such as inter-city bus services have been seriously disrupted or halted due to the civil unrest and armed conflict during 2011. Travel by long distance bus services in Libya is not recommended at this time.
If travelling by road in post liberation Libya very high levels of situational awareness should be practised at all times. Fuel supplies and vehicle repair services may be disrupted and some roads and bridges may be damaged. Armed groups and dis-affected individuals, armed militias and detachments of foreign military and military contractors are active throughout Libya. The opportunity to inadvertently become involved in a violent confrontation or robbery is currently much higher than in many other countries in the region and caution should be exercised. If in doubt stop and take cover or if possible immediately depart the area to a safer location.
Libyan Airlines (http://www.ln.aero/index.php) previously operated many domestic air routes prior to the 2011 civil war, Buraq airlines was also developing a domestic route system see "Get in".
Previous scheduled services may take an extended time to restore, please check before ticketing for any service.