How Each Stage Fails

Each stage fails in a characteristic way — and the rest of this module is essentially a tour of those failures:

Observe fails through the limits of vision and perception (Vision & Perception — you can look directly at a hazard and not register it), and through anything that narrows attention: Fatigue, Distraction, and the tunnel vision of speed.
Decide fails through impairment that corrupts judgement — Alcohol's overconfidence, the misjudged gap, the risk not predicted, especially around road users whose behaviour you didn't anticipate (Children in Traffic, The Vulnerable Road User Picture).
Act fails through impaired reaction and coordination (alcohol and fatigue again), and through reaction distances stretched by the factors in Speed & Stopping Distances.

Notice that alcohol and fatigue appear under all three stages. That's not repetition — it's the point. They're so dangerous precisely because they degrade the entire chain at once rather than one link, which is why each gets a lesson of its own.

Key takeaways

Each stage has a signature failure: Observe → vision and attention limits; Decide → impaired judgement; Act → impaired reaction and stretched distances
Alcohol and fatigue wreck all three at once — degrading the whole chain, not one link, which is why they get their own lessons

Quick check

Why do alcohol and fatigue get their own lessons rather than sitting under one stage?

A) Because they're the most common causes of crashes in Kenya

B) Because they're the only impairments that are illegal

C) Because they mainly affect the Act stage

D) Because they degrade all three stages at once — observation, judgement and reaction together — rather than one link in the chain