Chapter 10. Validating frequently

“Stray too far out of your lane and your attention is immediately riveted by a loud, vibrating baloop baloop baloop.”

David Haldane[1]

In the 1950s, the California Department of Transportation had a problem with motorway lane markers. The lines were wearing out, and someone had to repaint them every season. This was costly, caused disruption to traffic, and was dangerous for the people charged with that task.

Dr. Elbert Dysart Botts worked on solving that problem and experimented with more-reflective paint, but this proved to be a dead end. Thinking outside the box, he invented raised lane markers, called Botts’ Dots. Botts’ Dots were visible by day or night, regardless of the weather. They didn’t wear out as easily as painted lane markers. Instead of relying just on drivers’ sense of sight, Botts’ Dots cause a tactile vibration and audible rumbling when drivers move across designated travel lanes. This feedback proved to be one of the most important safety features on highways, alerting inattentive drivers to potential danger when they drift from their lane.

Reducing unreliability

Getting feedback faster

Managing failing tests