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Common Accidents and Their Causes
combination The most common accidents with road trains are skidding, overturning and jackknifing, usually occurring when the centre of gravity is too high or too low, or when the road is wet or snow-covered. On dry pavement, skidding usually occurs with a very high centre of gravity.
Key Rules
- ✓The most common accidents are skidding, overturning and jackknifing
- ✓These occur when the centre of gravity is too high or too low, or when the road is wet or snowy
- ✓On dry pavement, skidding usually occurs when the centre of gravity is very high
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Conditions for Overturning and Jackknifing
combination The danger of overturning is greatest in a curve or during high winds. Jackknifing usually results from braking abruptly on a wet or snow-covered surface with a fairly low centre of gravity. Be alert and reduce speed to prevent these accidents.
Key Rules
- ✓The danger of overturning is greatest in a curve or during high winds
- ✓Jackknifing usually results from braking abruptly on wet or snow-covered roads with a low centre of gravity
- ✓The best prevention is being alert to risky situations and reducing your speed
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Potential Skidding Situations
combination Skidding, overturning and jackknifing are usually due to driving too fast, momentary distractions, steering errors, or braking abruptly. Miscalculating exit ramp space can cause a skid or overturn. When one wheel skids onto the shoulder it can send the vehicle into the ditch.
Key Rules
- ✓These accidents are usually due to driving too fast, distractions, steering errors, or abrupt braking
- ✓One wheel skidding onto the shoulder can send the vehicle into the ditch
- ✓Stay well within your lane and ensure no wheels cross onto the shoulder
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Tips to Prevent Jackknifing
combination Jackknifing usually occurs when reducing speed while negotiating a curve or turning. Consider articulation points and adjust speed to road conditions (wind, visibility, traction). When the jackknife angle exceeds 15°, it is the point of no return where regaining control is almost impossible.
Key Rules
- ✓Jackknifing usually occurs when reducing speed while negotiating a curve or turning
- ✓Adjust speed to road conditions considering wind, visibility and tire traction
- ✓When the jackknife angle exceeds 15°, it is the point of no return and control is almost impossible to regain
- ✓The best prevention is defensive driving: obey speed limits and treat other road users courteously
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Tire Inflation and Brake Adjustment
combination Improper tire inflation causes accidents. An empty double road train with over-inflated tires can jackknife if braking abruptly, especially on a hot day after long driving. Under-inflated tires can cause loss of control. Improperly adjusted brakes can also cause jackknifing.
Key Rules
- ✓An empty double road train with over-inflated tires can jackknife when braking abruptly
- ✓Under-inflated tires (slow leak or fully deflated) can cause loss of control
- ✓Improperly adjusted brakes can cause you to jackknife
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Common Accident Types and Their Causes
combination Skidding, overturning and jackknifing are the most common road train accidents, linked to centre of gravity height and road surface conditions.
Key Rules
- ✓Occur when centre of gravity is too high or too low, or when road is wet or snow-covered
- ✓On dry pavement, skidding usually occurs with a very high centre of gravity
- ✓Overturning danger is greatest in curves or during high winds
- ✓Jackknifing usually results from abrupt braking on wet/snow surfaces with a fairly low centre of gravity
- ✓Best prevention is to be alert for risky situations and reduce speed
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Potential Skidding, Overturning and Jackknifing Situations
combination These accidents typically arise from speed, distraction, steering errors and abrupt braking, and from tire and brake problems.
Key Rules
- ✓Usual causes: driving too fast, distractions, steering errors, or braking abruptly
- ✓One wheel skidding onto the shoulder can send the vehicle into the ditch — keep all wheels in the lane
- ✓Over-inflated tires on an empty double road train can jackknife under abrupt braking
- ✓Under-inflated tires (slow leak, flat) can cause loss of control
- ✓Improperly adjusted brakes can cause jackknifing