Driver Knowledge Tests

Where are the blind spots on a truck and bus?

Blind spots are the areas a driver can’t see when looking in their mirrors or by turning their head. They are reduced dramatically by proper mirror placement and use of cameras, but they are very difficult to eliminate.

Small vehicles, cyclists, scooterists and pedestrians are most at risk in large vehicles’ blind spots because they can remain in there for extended time periods without realising.

Truck blind spots

The main blind spots for a truck driver are:

  • Immediately behind the trailer, in a narrowing triangle. The longer the truck, the longer this triangle, so watch for road trains. This space means vehicles tailgating the truck are not visible to the driver. Pedestrians walking behind the truck are not visible, either
  • Immediately behind the cab (unless driving a day cab with a rear window), or the body of the truck, for example between a truck and trailer combination
  • Immediately in front of the bonnet (unless there’s a front mirror angled down on cab-over trucks; there’s no solution for conventional bonneted trucks). This can hide a child or smaller adult crossing the road while the driver is waiting at an intersection – never cross in front of a truck while it’s waiting to go, unless you’ve made eye contact with the driver
  • Next to the passenger door, out around 1-2 metres (unless there’s a top mirror), and in a gradually broadening arc extending around 45 degrees backwards behind the B pillar (depending on mirror placement)
  • Next to the driver’s door, out around 0.5-1 metres, and in a gradually broadening arc extending around 45 degrees backwards behind the B pillar (depending on mirror placement)
Approximate blind spots of a cab-over prime mover towing a semitrailer, assuming no side-top or front mirrors. Note that this particular model does have a front mirror pointing downwards so would have less of a blind spot immediately in front of the cab.

The driver will also find it difficult see the front quarter of the top metre or so of the truck or trailer, if it is taller than the cab. This presents a risk when low-speed manoeuvring around awnings and low tree limbs.

The red shape shows the above-cab blind spot. It’s common for drivers to hit low barriers, tree limbs, awnings, cables, etc, because they misjudge the height of the vehicle. This small truck would also have a blind spot in front and behind the vehicle.

Bus blind spots

Top view of a right-hand drive bus, facing right. The blind spots on the side depend on the mirror position, how much glass their is down in the doors, any cameras and how far forward the wing mirrors are.
Side view of a right-hand drive bus facing left showing approximate blind areas, depending on the mirror placement. The height of the driver and the size of the front screen affect how long the front blind spot is. The door creates a blind spot which is only partially covered by the mirror. The mirrors on modern buses tend to be on stalks forward of the A pillar, which gives for better coverage down the side of the bus.

What reduces blind spots for heavy vehicle drivers?

  • Top mirrors – convex mounted above the passenger window
  • Front mirrors
  • Low door glass
  • Cameras
  • Day cabs (i.e. one with a rear window as opposed to a sleeper unit)
  • Wing mirrors are set further forward than the A pillar (applies mostly to buses)

What increases blind spots for heavy vehicle drivers?

  • Poor weather
  • Passenger (can obstruct view)
  • Poor mirror placement
  • Dirty mirrors
  • Dirty windows
  • Sunstrike
  • Large loads
  • Tall loads
  • Tall seating position (e.g. the bottom of the windscreen on a Kenworth cab-over prime mover is over 2m from the ground; even an adult can be in the blind spot)
  • Opaque signage on windows (very common on buses)
Small back window with a 40 sign, and tinted glass don’t help the driver.
Signage on this side doesn’t affect the driver, but signage on the passenger side should be translucent so that if the driver turns around, objects outside are still visible.
This bus has a reverse-facing camera above the rear window to help with reversing

Darren is an expert on driving and transport, and is a member of the Institute of Advanced Motorists

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