Driving in Dakar
Dakar, the capital of Senegal, has the most heterogeneous roads I’ve ever seen. A few shiny, modern cars weave between a fleet of beat up taxis. People hang off the back of the local buses, while the long-distance ones to Touba Mosque are lit up garishly. Motorcycles sneak between larger vehicles, children run up offering snacks at any delay in traffic, and carts are pulled by blinkered horses. Lanes are mostly suggestions, subservient to cars muscling their way through and the rich language of horns. (This is a second-hand anecdote, but I’ve heard of a taxi that connected the horn to the windshield wipers to make it easier to blast them repeatedly.)
If you’ve never seen a road like this, it might not make sense how this sort of thing works without crashing. It became a lot clearer to me when I saw a crash. A gnarl of traffic in a busy intersection suddenly stops; two drivers get out and look at each other’s cars. One car clipped another rear bumper. Nothing major. They look at each other for a few charged seconds, look at their cars, then both shrug and get back to driving. Another dent to the list. Time elapsed: half a minute at most.
A heterogeneous road is a slow road. The speed is set by the horses, not the average desired speed of everyone there. The variability and information density of a given road state may be orders of magnitude higher than the average road in the US, but the consequences of getting it wrong are usually lower. According to the locals, the only issues are when brash out-of-towners come to visit; speeding along sparse desert roads, they fail to adjust their speed for the tangled knot of civilization and go considerably faster than horse speed.
When a systems-oriented nerd looks at an artifact of modern operational design, they often come away totally starstruck. Look at this triumph of logistics! The dance of grocery store supply chains! The power of just-in-time warehousing! It seems to be so profoundly complex that it requires highly skilled stewards constantly keeping the flame lit. And crucially, this leaves you assuming that anything less will cause modern civilization to crumble into the sand. I was guilty of this as well at one point: I correctly predicated COVID being a major threat months in advance, but I incorrectly predicted months in advance that the COVID-induced supply chain crush would dramatically alter our modern way of life. Instead, we had shortages of a handful of specific items for a whole, followed by corresponding gluts.
Thinking that modernity will crumble if the dance of cargo ships gets out of whack is exactly the same error as assuming that the roads in Dakar must be horrific open-air murder festivals. You need the constraints and guarantees of modernity — Follow the lights! No horses! — if you want to go as fast in the city as you do in the desert and keep your shiny 70k car in pristine condition. If that’s your conception of road, then streets like Dakar’s seem impossible and unworkable. But when faced with a much broader and uncontrolled range of inputs, people will naturally slow down, communicate more, accept a few dings with grace, and muddle through. When modern systems break down, that muddle is capable of doing half of just about anything.