The section east of Middelburg has been significantly improved, including a northern bypass of Mbombela,[2] and now features some new grade-separated junctions.

As the R104 provides access to the Rustenburg Central Business District, the N4 turns south-east and bypasses the city centre to the south as a two-lane single carriageway freeway.

Adjacent to the Waterfall Mall of Rustenburg, the N4 meets the R24 road, which provides access to the cities of Magaliesburg, Krugersdorp and Johannesburg in the south-east.

From Kroondal, the N4 continues eastwards for 36 kilometres, encountering the Marikana Toll Plaza, bypassing Mooinooi, to reach the town of Modderspruit (Bapong), where it meets the R556 road which provides access to the resort of Sun City next to the Pilanesberg.

[3]: 28  The N4 proceeds eastwards for 13 kilometres to encounter the Brits Toll Plaza and cross into the Gauteng Province just south of Ga-Rankuwa.

The N4 proceeds eastwards for 25 kilometres to leave the City of Tshwane Metropolitan Municipality and reach the town of Balmoral in Mpumalanga Province, where it meets the northern terminus of the R545 road.

[3]: 30  After the interchange with the R555 and R544 routes south of the eMalahleni city centre, the N4 continues eastwards, meeting the eastern end of the N12 national route from Johannesburg (westbound only),[3]: 30  to bypass Middelburg to the south (where a tollgate is located just before the first Middelburg off-ramp), with the R575 and the R35 roads providing access to the city centre.

[3]: 30 From the N11 off-ramp, the N4 goes eastwards for 57 kilometres to meet the R33 road, which provides access to the town of Belfast (eMakhazeni) just to the north.

From eMakhazeni, the N4 continues eastwards for 22 kilometres to Machadodorp (eNtokozweni), where it meets the R36 route and crosses the Elands River.

[3]: 30 As the old road through Nelspruit Central is designated as the R104 (Samora Machel Drive), the N4 bypasses the city to the north on a newer highway (opened on 13 June 2010[2]), crossing to the northern side of the parallel Crocodile River, passing by Riverside (where it meets the R37) and through the Lowveld National Botanical Garden, before joining the old alignment east of the city and crossing back to the south of the Crocodile River.

From Mbombela, the N4 continues eastwards for 100 kilometres, following the Crocodile River (which makes up the entire southern border of the Kruger National Park), meeting the north-eastern terminus of the R38 road at Kaapmuiden and passing by the Nkomazi Toll Plaza just east of Kaapmuiden, through Malalane, to reach the Lebombo Border Post with Mozambique at Komatipoort, where it crosses the Komati River and becomes the EN4 road which provides access to Maputo, the capital city of Mozambique (90 kilometres away).

As there is now a northern bypass in Mbombela (Nelspruit; opened on 13 June 2010[2]), the old route through the city centre (Samora Machel Drive; 17 km) has also been re-designated as the R104.

[6] However, two western sections of the N4 have been made since then: Originally, the N4 ran westwards from the Proefplaas Interchange through the Pretoria CBD on regular city streets and then exited the CBD westbound on Vom Hagen Street towards Hartbeespoort Dam to become the Magalies Freeway, a 20 km tolled dual carriageway (two lanes in each direction; with a toll gate at either end of the freeway), completed in the early 1990s, before following the R511/R513/R512 regional routes over the Magaliesberg to meet the single-carriageway freeway built in the 1980s to a point northwest of Pretoria.

The Magalies Toll Freeway, which is a tolled dual-carriageway motorway with two lanes in each direction, begins at the junction with the R55 in Pretoria West and heads westwards for 18 km (with one off-ramp junction north of Atteridgeville) before abruptly ending south-east of Hartbeespoort (east of Pelindaba) at an off-ramp junction, where the road southwards connects to Pelindaba and Broederstroom (7 km away) and the road northwards connects to the R511 road to Hartbeespoort (7 km away).

[7] At the Proefplaas Interchange with the N1, the N4 now joins the N1 north (co-signed) up to just before the Pumulani Toll Plaza, where it splits off westward towards Rustenburg to become the Platinum Highway.

[8][9] The Pampoen Nek Pass is an extension of the R512 route, starting from the R512's interchange with the R560 route (just after the R512 bridge crossing over the Hartbeespoort Dam's western edge west of Broederstroom) and going north for 6 kilometres up to the R512's interchange with the N4 south of Brits, where the Pampoen Nek Highway joins the N4 Westbound.

They operate the entire route from the M10 (Solomon Mahlangu Drive) off-ramp approximately 10 kilometres east of the Proefplaas Interchange to the Lebombo border.