Roadcraft defintions Flashcards
System of Car Control definition
The system of car control is a way of approaching and negotiating hazards that is methodical, safe and leaves nothing to chance. It involves careful observation, early anticipation and planning and a systematic use of the controls to maintain your vehicle’s stability in all situations.
How does roadcraft define a hazard
‘Anything which is an actual or potential danger’
Define Actual danger
‘Where the law or the rule of the road places the onus upon the driver to ensure that it is safe before they continue.’
Define potential danger
‘Where common sense or road sense suggests that certain safety precautions be taken before entering the danger area’.
The 5 things to do when approaching a hazard
Observe, Anticipate, Prioritise, Decide what to do, Act
What is the safe driving rule
Always drive so that you can safely stop within the distance you can see to be clear on your own side of the road.
What is the purpose of a driving plan
The purpose of a driving plan is to put you in the correct position at the correct speed, in the correct gear at the correct time
What should be considered in the driving plan
- What can be seen
- What cannot be seen
- What might reasonably be expected to happen
- Which hazard represents the greatest threat
- What to do if things turn out differently from expected.
The 3 things to do when you see a road sign
Observe, understand, and react
What is the tyre grip trade off
There is a limited amount of tyre grip available. This is shared between accelerating, braking and steering forces.
Define acceleration sense
Acceleration sense is the ability to vary the vehicle speed in response to changing road and traffic conditions by accurate use of the accelerator, so that you use the brakes less or not at all.
Why does a skid develop
A skid develops when one tyre or more losses normal grip on the road, causing an involuntary movement of the vehicle. This happens when the grip of the tyre on the road becomes less than the force or forces acting on the vehicle.
What is the limit point
The limit point is the furthest point to which you have an uninterrupted view of the road surface.
On a Left HB drive the limit point is where the edge of the road meets the central white line/ centre of road.
What is a double apex
A corner which has a ‘tightening’ curve. In this bend the curve that the driver initially sees on the approach continues to tighten so the curve is much sharper than expected
When is a pulling vehicle most stable
A moving vehicle is most stable when its weight is evenly distributed, its engine is just pulling without increasing road speed, and it’s travelling in a straight line.
What are the three forces that reduce stability
Accelerating, braking, steering.
How does crown camber effect steering on a left hand bend
On a left-hand bend, camber increases the effect of your steering because the road slopes down in the direction of the turn.
How does crown camber effect steering on a right hand bend
On a right-hand bend, camber reduces the effect of steering because the road slopes away from the direction of the turn.
What is super elevation
Super elevation is where the whole width of the road is banked up towards the outside edge of the bend, making the slope favourable for cornering in both directions (similar to banking on a race track).
What should you consider when position your vehicle for cornering
When positioning your vehicle for cornering you need to consider Safety, stability and view however you should always be prepared to sacrifice your road position for safety.
How does the limit point help you judge the appropriate speed for a bend
The limit point gives you a systematic way of judging the correct speed to use through a bend. If the bend tightens, the limit point will appear to move closer so reduce your speed accordingly.
What should you do with information
Take, use and give
What is brake gear overlap
Brake gear overlap is the simultaneous use of the gears and brakes. BGO is commonly misused but if used correctly as part of a planned approach it can be beneficial.
What is understeer and what is oversteer
Understeer is the tendency of a vehicle to turn less, and oversteer is the tendency of a vehicle to turn more, in response to a given turn of the steering wheel.
What are the three situations where brake gear overlap might be apprpriate
- Going downhill
- Into a sharp right or left turn with a vehicle close behind or approaching
- Low speed junctions with a vehicle close behind or approaching
What is a single stage overtake
Where you’re able to overtake immediately- approaching overtaking and returning to your side of the road in one continuous manoeuvre
What is a three stage overtake
Where other hazards require you to take up a following position before you can safely overtake
What are the 5 overtaking specific hazards to consider
Junctions
Lay-bys
Driver attitude
Road surface
Weather conditions (standing water)
How much of a gap should you leave when overtaking cyclists and horses
1.5m when overtaking cyclists
2m when overtaking horses (less than 15mph)
stopping distance formula
Thinking distance + Braking distance = Stopping distance
The 5 benefits of leaving “tyres and tarmac”
- Allows you room to pull out and around the vehicle if it stalls or breaks down
- Enables you to see further up the road
- Leaves a space for filtering motorcycles and cycles to use
- Gives you a buffer if the vehicle in front rolls back towards you if you are facing uphill
- It gives you an escape route if a vehicle is approaching from behind and is unable to stop in time.
Give 3 observation links
Cluster of lamp posts = look out for a roundabout ahead
Single lamp post = Look out for the exit point of a junction
No gap in trees ahead = Look out for the road to bend
Things to consider when overtaking
- Don’t overtake with no view
- Don’t cause others to alter speed/position
- Allow plenty of time
- Be prepared to abort
- Avoid conflict
- Don’t overtake 3 abreast
- Do not overtake on the Nearside
Stopping distances
20mph - 40ft (2)
30mph - 75ft (2.5)
40mph - 120ft (3)
50mph - 175ft (3.5)
60mph - 240ft (4)
70mph - 315ft (4.5)
100mph - 600ft (6)
3 statutory exemptions for police
- Speed limit
- Red lights
- Keep left bollards
4 causes of a skid
- Too fast for the circumstances
- Harsh acceleration
- Excessive or sudden breaking
- Coarse steering
What does “anticipating” hazards do
Anticipating hazards gives you extra time. The more time you have to react to a hazard the more likely it is that you can deal with it safely.
POWDERS
- Petrol
- Oils
- Water
- Damage
- Electrics
- Rubber
- Servicing
What are the 5 benefits of a good following position
You have a better view of the road ahead which can be extended on both sides
You can see when it’s safe to move up into the overtaking position
You can extend the braking distance of the car behind if they are following closely behind
You have time to react if the car in front brakes suddenly
You get less spray from the vehicle in front in wet conditions,
When can you cross a solid white line
You may only cross it if you can see it’s safe to do so, and:
You need to turn into a property or side road, OR
You’re overtaking a parked vehicle or a cyclist, horse or road maintenance vehicle that is travelling at 10mph or less.
What are the three types of hazards
Physical features (junctions, bends, road surface)
The position of movement of other road users
Weather conditions
