The Controlled-Access Exception

Not every road is open to everyone — and the exception catches people out precisely because the mixed-use default is so universal everywhere else: controlled-access expressways are legally restricted to four-wheeled motorised vehicles only.

The clearest example is the Nairobi Expressway — itself a Class A, four-lane dual carriageway. Under Gazette Notice No. 11326 (31 December 2020), the following are legally prohibited from using it: motorcycles (including boda bodas), bicycles, scooters, tuk-tuks, wheelbarrows and handcarts, pedestrians, and skaters. Access is restricted strictly to four-wheeled vehicles and above. This isn't a courtesy convention — enforcement includes fines up to KES 20,000 and impoundment, with camera surveillance and highway patrols along the route.

Why this rule exists: the expressway's high design speed makes it fundamentally unsafe for anyone without the protection and speed capability of a four-wheeled vehicle. There are no dedicated lanes, shoulders, or escape routes designed for a boda or a pedestrian at those speeds. Rather than relying on every driver to be careful around a far more vulnerable road user at 80+ km/h, the safer design choice was to separate them entirely.

The reverse rule matters just as much: motorised vehicles and motorcycles are prohibited from using pedestrian walkways and dedicated cycle lanes. Nairobi's non-motorised transport (NMT) infrastructure — the walkways and cycle lanes built along a number of city streets — is legally off-limits to cars and motorcycles, including for parking. Riders and drivers caught using these lanes face prosecution and licence suspension, and can be held liable for the cost of repairing damage to the infrastructure.

The two rules are the same principle pointing in opposite directions: where mixing would be lethal, the law separates — excluding the vulnerable from high-speed space, and excluding vehicles from protected space.

The habit to build: road classification tells you the default mix, but always check signage for a specific restriction — especially on newer, high-speed infrastructure like expressways and bypasses, where the default mixed-use assumption doesn't hold.