The System of Car Control — used by police, IAM and RoSPA advanced drivers to negotiate every hazard safely and efficiently.
Chapter 3 — Roadcraft 2025
A hazard is anything that is an actual or potential danger — junctions, bends, parked vehicles, pedestrians, weather conditions, road surface.
The system gives you a methodical way of processing information and applying observation and anticipation so that you recognise and negotiate hazards safely.
It consists of processing information and four phases — Position, Speed, Gear and Acceleration. Each phase develops out of the one before.
As road conditions change, you re-enter the system at the appropriate point and continue through it in sequence. If a new hazard arises, re-apply the system and consider all phases in sequence.
"Driver error is a feature of nearly all collisions on the road. The system of car control aims to increase your safety by providing a systematic approach to hazards."— Roadcraft, Chapter 3
The Core Concept
Processing information is central to the system — it runs through and feeds into all the phases. Before anything else, ask yourself two questions:
"What information do I need about the road conditions, the behaviour of other road users, and actual and potential dangers?"
"What do other road users need to know about my intentions?"
Roadcraft uses the memory aid TUG — Take, Use and Give information.
Continuously assessing information runs through every phase of the system. You never stop reading the road.
Look all round you. Scan to the front and sides, including blind spots. Use your mirrors at appropriate points. Use all your senses — sight, sound, smell, physical sensations.
Use what you've gathered to plan how to deal with the hazards you identify. If new hazards arise, consider whether to re-enter the system at an earlier phase.
Signal if it could help other road users — indicators, horn or flash of lights. Give your signal in good time. Remember: the position of your vehicle also gives valuable information.
The Purpose
The system is a decision-making process that enables you to efficiently assess and act on information that is continuously changing. It gives you more time to react — vital in complex, demanding situations.
The system gives you a structured method for rapid decision-making. This reduces decision time and gives you more overall time to react in complex, high-pressure situations.
The system involves careful observation, early anticipation and planning, and systematic use of the controls to maintain your vehicle's stability in all situations. Nothing is left to chance.
Driving hazards come singly and in clusters, overlap and change all the time. The system accounts for this continual flux — you, the driver, are the flexible element at its centre.
Phase 1 of 5 — Runs Throughout All Phases
Processing information introduces the system and continues throughout. It is not a one-off action — it underpins everything and enables you to adapt the system to changes in road circumstances.
Take information through all your senses. Scan to the front, sides and rear, including blind spots. Use mirrors at appropriate points. Sounds such as a horn or siren warn of other road users. Smells such as diesel can alert you to spills ahead.
Observation and anticipation are inseparable. Good observation gives you early warning. Anticipation means reading the road and extracting the fullest meaning from your observations.
Scanning: Drivers who rapidly scan the whole environment have a much lower risk of incident. Scan far distance, middle distance, foreground, sides and rear continuously
Mirrors: "Whenever you consider changing position or speed, always check first what is happening to the front, sides and behind you. You must check your mirrors at this point"
Signals: "Give a signal whenever it could benefit another road user." Your position on the road also communicates your intentions
Commentary driving: Describe what hazards you can observe and how you plan to deal with them. Practise asking "What if…?" to sharpen your anticipation
Phase 2 of 5
"Position yourself so that you can negotiate the hazard(s) safely and smoothly."
The ideal road position depends on safety, observation, the size of the vehicle, traffic conditions, road layout, and making your intentions clear to others. Always consider safety before anything else.
Roadcraft identifies three positions: nearside (left of lane), central (midway, good margins either side), and offside (closer to centre line). Any of these should be sacrificed for safety.
Left turn — nearside: Best position for left-hand turns. "In a smaller vehicle, consider a position towards the left of the road." Do not swing wide (swan-necking)
Right turn — offside: "Alter your position towards the centre of the road to make the turn in good time." Provides better view into the junction you're entering
Bends: Nearside position gives early views through right-hand bends; offside position gives early views on approach to left-hand bends — always within your lane
Improve your view: Moving towards the centre of the road improves your view into nearside junctions and makes you more visible to drivers pulling out from them
Phase 3 of 5
"Adjust your speed as necessary. Use the accelerator or brake to give you the correct speed to complete the manoeuvre safely. Make good use of acceleration sense."
Acceleration sense is "the ability to vary vehicle speed in response to changing road or traffic conditions by accurate use of the accelerator, so that you use the brakes less or not at all." It reduces fuel use and wear.
Braking should be progressive and increased steadily — smooth braking is safer and uses less fuel. Plan to brake early. Remember: braking on a bend reduces rear tyre grip and can unbalance the vehicle.
Safe stopping rule: "Always drive so that you can stop safely within the distance you can see to be clear on your own side of the road" — the guiding principle of all speed decisions
Tapered braking: Apply gentle pressure first, increase progressively. Releasing the brake gently at the end maintains vehicle balance and comfort for passengers
Engine braking: Releasing the accelerator in a lower gear provides useful slowing force without brake wear. "On a bend this reduces stability" — so avoid harsh braking in corners
Limit point on bends: Where both edges of the road appear to meet. If it moves away — safe to proceed; if it draws closer — you must slow to match your stopping distance
Phase 4 of 5
"Once you have the correct speed for the circumstances, engage the appropriate gear for that speed."
Correct use of gears depends on accurately matching the gear to the road speed and using the clutch and accelerator precisely. The goal is to be in the correct gear for every road speed and traffic situation.
Roadcraft is clear: "The principle is that brakes are to slow, gears are to go." Never use the gearbox to slow the vehicle. Block gear changes (e.g. 5th to 3rd) are perfectly correct when they match the correct speed.
Match gear to speed: "Your vehicle can only increase speed if the engine can deliver the power, and it can only do this effectively if you're in the correct gear." Under/over-gearing reduces control
Block changes are fine: "Engage a chosen gear without going through an intermediate gear first." There is no need to go 5th → 4th → 3rd if the speed matches directly to 3rd
Don't change gear on a corner: "Don't change gear while cornering. It destabilises the vehicle and requires you to take one hand off the steering wheel" — Roadcraft, Chapter 6
Automatics: The system still applies. "It's easy to become lax. Some automatic drivers drift into the habit of losing speed late, entering bends while still reducing speed" — avoid this
Phase 5 of 5
"Taking account of your speed, the presence of other road users, and the road and traffic conditions ahead, choose an appropriate point to accelerate safely and smoothly away from the hazard. Adjust acceleration to the circumstances."
This is the culmination of the system. You are now in the right position, at the right speed, in the right gear. If the way ahead is confirmed safe, drive away smoothly and progressively.
On bends, use the accelerator to maintain a constant speed round the curve. "A constant speed keeps your weight evenly distributed front and rear, and ensures maximum tyre grip." Do not increase speed mid-bend.
Confirm before committing: Take a final observation before you accelerate away from a junction. The situation may have changed since your last look
Acceleration sense: "Vary vehicle speed in response to changing conditions by accurate use of the accelerator, so that you use the brakes less or not at all" — smoother, safer, more fuel-efficient
Tyre grip trade-off: "The harder you accelerate, the less tyre grip you have for steering." On a slippery surface or mid-bend, accelerate very gently and progressively
Coming out of a bend: As the new road view opens rapidly beyond the apex, conditions permitting, consider gentle acceleration — not full throttle until the road is fully clear
How to Apply It
"Consider all phases of the system on the approach to every hazard, but you may not need to use every phase in a particular situation." A simple hazard may require only some phases.
"Take, use and give information throughout to constantly re-assess your plans. Be ready to return to an earlier phase of the system as new hazards arise." The system is a loop, not a one-pass sequence.
Planning through a series of hazards — effectively treating them as one complex hazard — can help you make progress as well as prevent unsafe driving. Scan from the furthest you can see back towards where you are now.
"With practice, the system will become second nature and form a sound basis for developing the finer points of your driving skill." At first, name each phase out loud. Review your performance after each journey.
"The system works if you use it intelligently and proactively and adapt it to circumstances as they arise."— Roadcraft, Chapter 3
"If you're distracted or preoccupied, consider giving a running commentary to help you to focus on working through the system as you approach each hazard."— Roadcraft, Chapter 3
System Applied — Roadcraft Examples
System Applied — Roundabout
Advanced Technique — Chapter 3, Roadcraft 2025
"The individual phases of the system of car control are usually applied separately. The principle is that brakes are to slow, gears are to go."
However, in specific circumstances, it may be helpful to overlap braking with the gear change by braking normally but changing the gear towards the end of braking.
If you use this technique, it must be part of a planned approach to a hazard. Begin applying the system at the same time and in the same place as you would normally. The system is not compressed.
When learners first practise the system, they keep braking and gear selection completely separate. With tight turns, braking too far back can confuse other drivers — a following driver may think you're stopping, or an approaching driver may turn ahead of you.
When brake/gear overlap is appropriate:
Left or right turns — with a vehicle close behind or an approaching vehicle. Prevents sending confusing signals to other drivers about your intentions.
With a vehicle close behind or approaching — where braking too far in advance would cause confusion or unnecessary disruption to traffic flow.
Example: turning left into a side road partway down a hill. Without overlap, the vehicle will accelerate the moment you take your foot off the brake before selecting gear.
Summary Card — Based on Roadcraft 2025
Smart Driving Academy — Advanced Driving Series
smartdrivingacademy.ieSource: Roadcraft — The Police Driver's Handbook, 2025 Edition