Confessions of a Recovering Engineer: Transportation for a Strong Town

Summary

Introduction

A devastating conversation between an engineer and a resident that pass through each other.

The depicted engineer bases their argument on the traffic projection and engineering standard that is entirely focused on the designing for high speed traffic (highways) and totally blindsided by the common sense.

Embedded values

Every decision is built on values, either explicit or implicit. Engineers often think that their design principles and practices are value free but that’s far from the truth.

Engineers know how to design for high speed but believe that they cannot control the speed but it’s about enforcement. However, it is possible to design for low speed by reversing the practice of high speed design.

There is rarely any acknowledgement of the opposite capability, however: that slow traffic speeds can be obtained by narrowing lanes, creating tighter curves, and reducing or eliminating clear zones.

The values embedded in engineering practice is in order of traffic speed, volume, safety, and cost. But most humans order them differently: safety, cost, volume, and speed.

Although civil engineering is an old discipline, the specific practice of designing for the high speed cars is young, only from the post World War II. It may have been true that building roads and connecting far away places together facilitated the economic growth for a while, but now the system is mature. A good highway network is alredy finished decades ago.

The project should also be called in a value-neutral way. Road widening project shouldn’t be called “road enhancement”. “Tree removal” should be called “tree removal” rather than “clear zone enhancement”.

the difference between a road and a street

Road: a high-speed connection between two places Street: a platform for building community wealth

For road, increasing speed adds value. For street, decreasing speed adds value. At the middle, there exist stroads that are terrible at both. Stroads are dangerous and expensive, while failing to build wealth around it.

Stroad is the worst of the both. It sucks at moving cars quickly and sucks at building wealth. It is also the most dangerous form.

Whose mistakes do we forgive?

Early highway engineers came up with the idea that instead of trying to fix people’s behaviors (e.g., DUI), we can engineer the environment more forgiving to reckless driving.

Wider lanes, shoulder, recovery zones, removal of trees saved countless lives on the roads. The problem is that the same principle was applied to the streets.

Such design reduces the perceived risk of drivers and nudge them to speed more. The opposite is also true. If a driver perceive higher risk, they slow down.

If the goal is to forgive the mistakes of the driver, this design is doing the opposite. It tricks drivers … into making more mistakes – more costly mistakes – than they otherwise would.

Designing a forgiving street is the opposite approach to designing a forgiving road. Instead of widening lanes, we narrow them. Instead of smoothing curves, we tighten them. Instead of providing clear zones, we create edge friction. Instead of a design speed, we establish a target maximum travel speed.

On our streets, we want the price paid for mistakes to be paid in fender benders and shattered headlights instead of in human lives and suffering. Sandra Zemtsova should have hit a curb or a bollard long before she ran into Destiny Gonzalez.