A Theory on Formation of Potholes in Nairobi

Chris Orwa
#WhatIsARoad
Published in
3 min readOct 25, 2016

A few weeks ago I was invited to provide data analysis assistance to the project #whatisaroad — an initiative to map potholes in Nairobi and engage the county government on infrastructure through data. We set up a mapping party and I volunteered to cover Kayole and Buruburu Estates. Off with a pen, notebook and phone camera, I gathered information on a location of potholes, their sizes, directions, and landmarks. The first observation was that most potholes along Kayole Spine Road developed at junctions or intersections.

On this phenomenon, I got reminded of a concept in Systems Theory that states,

‘Systems expose vulnerabilities at points in which they interface with other modules’.

As an example, a shirt begins to wear off from the sewn joints — a car wear off from connecting parts. Using the same analogy, it safe to conclude that the trunk road and the feeder roads are not built as a single continuum of asphalt rather separately. Given great breaking force gets applied by cars when they approach junctions, Shear Force pulls the two strata asunder much like continental plate tectonic movements . The conclusion is supported by the next set of observation that shows potholes developing at speed bumps. These ‘structures’ are normally built after road completion and great breaking force gets applied by cars at this points.

But herein is a third observation that shows bumps contributing to the development of potholes. These types of potholes manifest as ridges emanating from the speed bumps — prevalent in Buruburu and parts of Kayole. A perfect explanation for these potholes lies in Gilberts Tessellation — a mathematical model built by Edgar Gilbert whom after being consumed by boredom decided to study how cracks form on dry mud and glasses. Turns out the cracks don’t form in a random pattern rather after an initial fault line develops the next crack is perpendicular to it.

We can avoid potholes by building all road sections as a single continuum! However, there hasn’t been a proved method of building roads in single continum — perhaps an innovation awaiting in the civil engineering sector. It is also worth mentioning that drainage is one of the major contributing factors to road degradation and thus might outweigh how roads are built.

Got a pothole to report? Or a road in desperate need of repair in Nairobi? Follow @whatisaroad & highlight yours using hashtag #WhatIsARoad . Remember to include a photo of the pothole with the road and closest landmark.

View the map of potholes in Nairobi here: https://whatisaroad.crowdmap.com/

--

--