Overall features, length and condition and
Ghardaia in Algeria The Trans-Sahara Highway has a length of about 4,500 km of which about 98% has been paved. It passes through three countries:
Algeria,
Niger and
Nigeria. However, an additional 3,600 km of linked highways to
Tunisia,
Mali,
Chad and
Mauritania are considered by planners to be integral to the Trans-Sahara Highway network. The six member countries represent 27% of the continent's GDP and 25% of its population. The 1,200 km of the highway in Nigeria are part of that country's national paved road network and include nearly 500 km of four-lane divided sections, but highway maintenance is frequently deficient and parts of the road may be in poor condition. About half the highway, over 2,300 km, lies in Algeria and is mostly in good condition, with the newest sections south of
Tamanrasset. From the Algerian border town of
In Guezzam to 'Point Zero' on the Niger border is now sealed, with a sand berm extending to either side to disrupt migrant trafficking. Niger has 985 km of the highway and in 2023 some 900 km had been asphalted, although parts are in poor condition in the south. Further details are given below. Another crossing of the Sahara was proposed for the
Tripoli–Cape Town Highway (Trans-African Highway 3) but this route requires a great deal more construction, faces problems of instability and lawlessness in southern Libya and northern Chad, and is not likely to stimulate trade to the same extent as TAH 2. It may be decades away from completion. Two other Trans-African Highways cross the Sahara, but at its edges. In 2005 the
Cairo–Dakar Highway (TAH 1) in the west along the
Atlantic coast became the first fully sealed highway crossing the Sahara from north to south (barring a few kilometres in No Man's Land between Morocco/Western Sahara and Mauritania). The
Cairo–Cape Town Highway (TAH 4) follows the
Nile in the east, the previous long unpaved sections in Sudan, Ethiopia and Kenya have since been significantly improved. The highway from Nanyuki in Kenya to Moyale at the Ethiopian border is an excellent tarmac road. The roads in Ethiopia and Sudan are all tarmac of good quality as of October 2020. Announced in 2018, by 2019 a third trade route opened between
Algeria and
Mauritania, and following pandemic delays, in 2024 opened officially to non-freight traffic, but has yet to be classified. Established during the French colonial era as a link between Algiers with
Dakar to avoid what was then the
Spanish Sahara on the Atlantic, it was closed in 1963. Currently the tarmac ends at Hassi Abdelah, the Mauritanian frontier post 75km south of
Tindouf. It resumes some 790 kilometres later near
Zouerat, passing through
Ain Ben Tili and
Bir Moghrein. ==Route==