Free Climbing controlled by traffic lights

No rule without an exception. I did find that one through Bill. A climber can use cracks to secure himself. You need a cam of the right size for that. Modern ones are based on eccentric panels and are high-tech.

Placing a cam in a crack

Does the cam fit the crack? Look at the traffic light color. Green holds, yellow should hold while the next size would be better. Red doesn’t hold.

Rangefinder

Climbing is easier than controlling an enterprise.