Johannesburg is heavily dependent upon freeways for transporation around the city due to its location 1500 metres above sea level, far from the coast or any major bodies of water. There are 10 freeways in the metropolitan area: the N1, N3, N12 , N14 , N17 , R21 , R24 , R59 , M1 and M2 .

The N1, N3, and N12 form the Johannesburg Ring Road around the city. The N14 connects the West Rand with Pretoria, and could possibly form part of a future Johannesburg second outer ring road. The N17 connects the Johannesburg Central Business District and southern parts of the city with Springs on the East Rand and the province of Mpumalanga. The R21 connects Johannesburg International Airport with Pretoria. The R24 connects central Johannesburg to the airport. The R59 connects Johannesburg with Vereeniging in the Vaal Triangle. The M1 runs the length of the city north-south, from Soweto to Buccleuch, where it becomes the N1. The M2 runs the length of the central part of the city east-west, from Germiston to Main Reef Road .

The N1 between Johannesburg and Pretoria is now becoming severely overloaded. Reports suggest that the road carries 160,000 vehicles a day between the two cities. Especially during peak times, the road is gridlocked entering Johannesburg in the mornings and leaving it at night, as many people work in Johannesburg but live in Pretoria. As a result, the Gauteng Provincial Government has put in motion plans to alleviate heavy traffic congestion, which is likely to worsen. One plan that is scheduled to be completed before South Africa hosts the 2010 Football World Cup is the Gautrain : a rapid rail system with a north-south line between Johannesburg and Pretoria, and an east-west line between Johannesburg International Airport and Sandton. A new freeway has also been mooted, linking the northern part of Johannesburg with the western part of Pretoria, aligned along the existing R80 axis known as the Mabopane Freeway. It will run parallel to the N1.