North West

Its northern origin is Brits, North West at an intersection with the R511 as Van Velden Street, becoming Rutgers Street, in a southerly direction. Just south of Brits, the R512 meets the R566 road from Ga-Rankuwa.

The R512 continues southwards to meet the N4 highway (Platinum Highway). Just after meeting the N4, the R512 reaches an interchange with the Pampoen Nek Pass (which is coming from the N4 West in the west) and it leaves the southerly road to become the Pampoen Nek Pass south-eastwards, passing under the R104 route, to reach an interchange with the R560 route west of Kosmos Village. From the R560 interchange, it continues south-east, crossing the Magalies River & turning eastwards at a T-junction by Arrows Rest, bypassing the Hartbeespoort Dam to the south, to pass through the town of Broederstroom.

After Broederstroom (west of Pelindaba), by the Crocodile River, as the road eastwards connects to Pretoria, the R512 turns southwards, as Pelindaba Road, towards Johannesburg. Just after, the R512 crosses into Gauteng.

Gauteng

From Broederstroom, the R512 makes a 25 km journey to enter the City of Johannesburg Metropolitan Municipality and reach the Lanseria International Airport. The road then meets the R552 (6th Road) at Bultfontein and forms an interchange with the N14 highway (Pretoria-Krugersdorp Highway).

After crossing the N14 highway and its old equivalent, the R114, it heads south towards Randburg as Malibongwe Drive - formerly known as Hans Strijdom Drive. It passes through the lower-middle Cosmo City and Kya Sands townships before crossing the R564 Road (Witkoppen Road; Northumberland Avenue) and entering the more affluent Northriding and Olivedale suburbs. The R512 reaches an interchange with the N1 highway (Johannesburg Western Bypass) before continuing through Randburg as Malibongwe Drive, then West Street, to end in Linden, north of the Johannesburg Botanical Garden, at a junction with the M20.

Pampoen Nek Pass

As of 2018, the South African National Roads Agency (SANRAL) was constructing a shortcut for the R512 Route, from its intersection with the R560 route (north-west of Broederstroom) northwards up to just north of where the R512 and the R104 route split (west of The Elephant Sanctuary of Hartbeespoort), where there is a ramp onto the N4 Platinum Highway West, in a highway format.^[4][5][6]

The R512's junction with the R560 west of Hartbeespoort Dam is an off-ramp junction and the next and last junction just north of the R104 and R512 junction west of the Elephant Sanctuary is also an off-ramp interchange before the freeway goes westwards to join the N4 West.^[3]

It was built to reduce the traffic that occurs on the older longer section of the R512 through Damdoryn, which is also labelled as a high accident zone adjacent to Kosmos Village.^[7][8] It is meant to be a shortcut and to reduce the distance for travelers using the R512 to either join the N4 Highway West to Rustenburg & Sun City or to go to Brits.^[6] To some extent, this new route also reduces the traffic on the R511 route,^[8] which passes on the other side of the Hartbeespoort Dam (through Hartbeespoort Central) on its way to Brits, and long distance movements will no longer have to interfere with local traffic.^[8] This new road is to be used by motorists who want to travel from the Johannesburg Municipality (Sandton & Randburg) (and nearby areas, like Pretoria West) to cities like Brits, Sun City and Rustenburg.

On 3 September 2020, the Minister of Transport, Fikile Mbalula, together with the South African National Roads Agency and the Madibeng Local Municipality, officially opened the new road.^[2][3] This route, known as the Pampoen Nek Highway, is 6 kilometres in length^[3] from the R560 interchange to the interchange where the R512 turns north towards Brits (6 kilometres shorter than the old Z-shaped route passing by Kosmos Village, Damdoryn and the Elephant Sanctuary).