Scanning and the IPDE process
Good drivers do not just react. They look well ahead, spot what might happen and plan before they need to act. Driving courses across Canada teach this as a simple routine.
One common version is IPDE: Identify, Predict, Decide, Execute. Some handbooks use similar words, such as see, think, do. The idea is the same.
By the end of this topic you can
- You can scan ahead, to the sides and behind in a regular pattern.
- You can name the four steps of IPDE.
- You can predict what other road users might do.
- You can choose a safe action early and carry it out smoothly.
What you need to know and understand
- Identify: spot hazards and anything that could become a hazard, such as a child near the road or a car waiting to pull out.
- Predict: think about what each road user might do next and what could go wrong.
- Decide: choose your action, such as slowing, changing position or signalling.
- Execute: carry out your decision smoothly, then start the cycle again.
- Look well ahead, and also to the sides and behind. Check your mirrors about every five seconds.
- Watch for people in parked cars who may open a door or pull out.
- Take extra care at dusk and dawn, when others are harder to see.
IPDE in action
You are driving down a residential street at 40 km/h. You identify a ball rolling out from between parked cars. You predict a child may run after it. You decide to cover your brake and slow down. You execute by easing off the accelerator and braking gently, ready to stop. All this takes a couple of seconds, but starting early gives you room.
A scanning routine
- Look far ahead along your path, as far as you can see clearly.
- Sweep your eyes across the road, sidewalks and side streets.
- Glance in your mirrors about every five seconds, and before slowing or changing position.
- Check your speed briefly.
- Return your eyes to the road ahead and repeat.
Clues that something may happen
- Brake lights several cars ahead
- A car's front wheels turning at a side road
- Exhaust smoke from a parked car, meaning someone may pull out
- Pedestrians looking at traffic or standing at the curb
- Cyclists near parked cars who may move out to avoid doors
- A bouncing ball or a pet near the road
Common mistakes
- Staring at the bumper of the car directly in front.
- Forgetting the mirrors for long stretches.
- Assuming other road users will do the right thing.
- Deciding too late, which leads to sudden braking or swerving.
Test yourself: Scanning and the IPDE process
Answer each question, then read the explanation. Questions come in a random order each time.
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Sources: Ontario MTO Official Driver's Handbook, Driving along (ontario.ca); ICBC Learn to Drive Smart, See-think-do strategy (icbc.com). Independent guide, not affiliated with any licensing agency. Always check the latest official rules with your province or territory.