Nairobi, July 7 -- I have travelled the road from Kiganjo in Nyeri County to Nairobi, many times. At first, I was in secondary school. Afterwards, it was visiting relatives in Othaya, during which trips we would usually turn off towards Mukurweini, soon after Karatina town. Later, and more frequently, while serving as governor of Laikipia.

The road alignment has straightened (Thika-Kenol-Makutano) since I first travelled on it, and improved to a four-lane dual carriageway, now covering the entire length from Marua. The section between Thika and Nairobi is, of course, a much wider highway with four lanes on either side, and six in some sections. Towns along the highway have grown, except Kiganjo which gave way to Chaka.

The traffic has i...