Lessons from failed Nairobi traffic experiment

In the past week I keenly watched the Nairobi Governor’s experiment with roundabouts in the city. From what I gather the Governor and his team came up with the idea that eliminating roundabouts would ease the flow of traffic thereby saving Nairobians some valuable time.

However, as it turned out the experiment failed. Instead, the drums will leave the roundabouts and we should expect to have four-way intersections instead of roundabouts in the next few months. Now, there are several lessons from this failed experiment. First, did the Governor’s team collect data on road usage in the city? Did they collect information on how this varies by time of day and what patterns the distribution of vehicles follow? Did this data then inform the decision to get rid of the roundabouts?