Diamond Hill Toll Plaza and its secondary components stretch over several kilometres of rural highveld along the eastern track of the N4 toll road that links Gauteng with Mpumalanga and eventually Mozambique. At its core is the main plaza, announced from afar by lighting masts leaning inward and swelling the horizon to a dramatic apex. A suspended steel canopy floats over the articulated tollbooths and the associated safety kit, both exaggerating in perspective the direction of travel. Scattered along the highway in both directions are minor ramp plazas that borrow their design language from the main plaza and the theme of water tower reservoirs as landmarks.

In obvious contrast to the agility and tentative lightness of the main plaza that it faces onto, the control building is made up of pavilion-like sheds on stone plinths. Face brick panels in steel frames are cut open and glazed across corners. Squat passages connect through courtyards interspersed with corrugated steel water tanks and sparse indigenous flora amongst boulders that cover the surface.
Materials were sourced locally and applied responsibly. Masts, wing-like roofs and water towers invoke a strong sense of place.
Three main influences are apparent in the project: the most obvious is that of the programme and the pragmatics of procession illustrated in the main plaza. Secondly, the building forms were inspired by the agricultural vernacular, skilfully reinterpreted with a persuasive sense of proportion and composition. Thirdly, and most convincingly, the design responds to the landscape. The countryside setting is masterly exploited by inserting structures, unapologetically but not inconsiderately, into it. This response powerfully realises the aspirations of the client to have the project act as an urban-rural threshold.