Driving a heavy truck

By the end of this topic you can

• You can keep a safe space cushion around a heavy truck.
• You can plan a right turn that allows for off-tracking without swinging into other lanes unsafely.
• You can brake early and smoothly, allowing for weight and air brake lag.
• You can use your mirrors to watch the trailer and the blind areas around it.
• You can carry out a daily trip inspection before driving.

What you need to know and understand

• In Ontario, a commercial motor vehicle travelling over 60 km/h on a highway must stay at least 60 metres behind other vehicles, except when passing.
• On a turn, the rear wheels of a long vehicle follow a tighter path than the front wheels; this is called off-tracking.
• Heavy vehicles need far more distance to stop than cars, and more again on wet, icy or downhill roads.
• In Ontario, most large trucks built from 1995 with an electronically controlled engine must have a speed limiter set at 105 km/h.
• On Ontario freeways with three or more lanes each way, large trucks may not use the far left lane.
• Commercial drivers must inspect their vehicle daily and must not drive with a major defect.

Space all around the truck

Leave much more room ahead than you would in a car, so you can brake gently and avoid hard stops that shift the load. Watch for cars cutting into the gap; if one does, ease off to rebuild it.

You have large blind areas along both sides, behind and close in front. Check your mirrors every few seconds, and before any lane change, look long enough to see a small car that may be hidden beside the trailer.

Making a right turn

1. Check mirrors early, signal, and slow down well before the corner.
2. Keep the trailer close to the curb on approach to stop cars or cyclists slipping up your right side.
3. Drive further into the intersection than you would in a car before starting to steer.
4. Turn steadily while watching the right mirror to see where the trailer wheels are tracking.
5. If you need part of another lane, make sure it is clear and move only as far as you must.
6. Straighten up and check the mirrors again once the trailer has cleared the corner.

Braking, hills and weight

Weight makes a truck slow to stop and slow to speed up. Look far ahead, read traffic early, and start braking sooner and more gently than in a car. Air brakes have a small delay before they bite, which adds to stopping distance.

Before a long downhill grade, choose a lower gear at the top so the engine helps hold your speed. Riding the brakes all the way down can overheat them and make them fade. Load changes things too: an empty trailer can bounce and lose grip, while a full one takes longer to stop.

Common mistakes

• Starting a right turn too early, so the trailer wheels climb the curb or hit a post.
• Following at car distances, which leaves no room to stop smoothly.
• Relying on one mirror check before a lane change when a car may be hiding in a blind area.
• Using the service brakes constantly on a long downhill instead of a lower gear.
• Rushing the daily inspection and missing a defect.

Test yourself: Driving a heavy truck

Answer each question, then read the explanation. Questions come in a random order each time.