[1] The R300 begins at the Stellenberg Interchange with the N1 between Bellville and Brackenfell and heads south bordering between both towns.

[1] The entirety of the R300 Freeway is part of the proposed Peninsula Expressway, which is to be designated as the N21 and is to be a toll road.

[2][3][4] The proposed road is meant to extend the current R300 from its northern terminus (Stellenberg Interchange) with the N1 highway, past Durbanville, bending west, up to the Melkbosstrand and Blouberg coastal area.

[5] It is also meant to extend the current R300 from its southern terminus (Mitchells Plain) junction with the M7 route (Jakes Gerwel Drive) westwards, through Zeekoevlei, up to the Muizenberg and Westlake area.

[5] In August 2022 the Western Cape Department of Transport and Public Works announced the launch of an environmental impact assessment for the extension of the R300 from its current terminus at the N1 northwards to the R302 (Wellington Road).