Thika Road traffic:
where it stops, and why.

The shape of the road matters

Thika Road is not one road. Since the superhighway upgrade it has been two systems running side by side: the express lanes down the middle, which have no stops between interchanges, and the service lanes on either side, which carry matatus, local turns, boda bodas and everything entering or leaving an estate.

Almost every jam on Thika Road is a mixing problem between those two systems. Traffic slows where cars trying to exit cut across to the service lane late, and where matatus stopping at a stage back up into the lane behind them. The lanes themselves are rarely the limit. The junctions are.

Practical version: choose your lane by your exit, not by which one is currently moving. Drifting into the fast express lane and then needing to cross three lanes at Roysambu is how you end up stationary while the service lane you left is moving.

When it jams

Inbound, the build-up starts around 6:00am and the worst of it sits between 6:45 and 8:15. Leaving Githurai at 5:45 and leaving at 6:45 are not the same journey; they can differ by an hour. Outbound, the evening queue forms from about 4:30pm and does not properly clear until 8pm, later on Fridays and at month-end.

Three things reliably make it worse than normal: rain (add 30 to 60 minutes and expect the underpasses to flood first), school opening and closing days, and any incident in the express lanes. Because there is nowhere to go up there, a single stalled lorry past an interchange backs traffic up for kilometres in minutes.

Where it jams, going into town

• Githurai 45: stage activity and pedestrians spilling into the carriageway. Often the first thing that stops on a normal morning.
• Kahawa West and Kahawa Sukari: heavy estate traffic joining in a short stretch.
• Kenyatta University: term-time only, but during term it is a real delay.
• Roysambu / TRM: the classic. Matatu stages, pedestrian crossings and mall traffic in one place.
• Allsops, Ruaraka: the junction most Nairobi drivers name first, and with reason. Industrial turns plus a stage plus everyone exiting for Outer Ring.
• Garden City and the Ruaraka–Pangani stretch: where the volume from every estate behind you has already merged.
• Pangani and Muthaiga: the approach to town, where the road loses the width it had.
• Globe roundabout: the last squeeze into the CBD, and the one most affected by anything happening in town.

Going out in the evening, the same list runs in reverse, with the additions of the Ruiru and Juja exits, which back up onto the highway when the towns themselves are busy.

Alternatives that actually help

Most Thika Road "shortcuts" just move you into a smaller jam. These are the ones worth knowing:

• Eastern Bypass: if you are going to the airport, Embakasi or the Mombasa Road side, leave Thika Road at Ruiru and skip the city entirely. This is the single biggest saving available on this road, and the one people forget.
• Kamiti Road: a parallel run on the Kiambu side, useful from Kahawa Sukari towards Kiambu Road and Ruaka. It is narrow, so it rewards leaving early rather than leaving late.
• Outer Ring Road: exit at Allsops for Eastlands, Donholm and the airport. Since its own upgrade it is a genuine option, though it has its own evening peak.
• Mwiki and Kasarani local roads: only for reaching those estates. They are not a through route, and treating them as one puts you in an estate jam instead of a highway one.
• Kiambu Road: an alternative into town from the Ruaka side, but it congests badly on its own. Check before committing.

How Thika Road closures get announced

The A2 is a national trunk road, so planned works and closures come from KeNHA, usually on its social accounts a day or two ahead. NTSA and the traffic police post on incidents and diversions as they happen, and Nairobi County handles the city-end roads around Pangani and Globe.

The gap in all of that is the unplanned. Nobody issues a notice for a matatu that has broken down across two lanes at Allsops at 7:10am. That information exists only with the drivers who are already looking at it, which is exactly what Rada is for.