Driving tests

Where are blind spots on trucks and buses

Drivers have areas around their vehicle that they cannot see in the mirrors or by turning to look. These are called blind spots. Modern vehicles have fewer blind spots due to better mirror placement, cameras and bigger windows, but there are limitations.

Blind spots put other road users at risk, predominantly small, vulnerable ones like motorcyclists, cyclists, scooterists and pedestrians, but it’s also possible to be in the blind spot of a class 5 truck when you’re driving a class 2 truck – it’s not limited to small cars and two-wheeled vehicles.

Many road users have no idea about truck blind spots and absentmindedly drive in them for extended periods without realising the dangers. The following diagrams and descriptions of blind spots should help all roads users, from pedestrians to truck and bus drivers, understand the danger areas.

Truck blind spots

Blind spots for a truck driver where other road users can enter, assuming there’s no front mirror or top-side mirror, or reverse camera. Not shown are the blind spots caused by the A pillar and the mirrors – these keep the driver’s head moving to see around them, especially when approaching a roundabout or intersection

Cab front

For cab-over trucks, like the ones below, draw a line from the driver’s eyes past the bottom of the truck’s windscreen. This creates a wedge in front of the cab.

Cab-over vs conventional showing the different shape of the blind spot in front of the vehicle
On a Kenworth, where the bottom of the windscreen is over 2 metres tall, this is a huge blind spot immediately in front of the truck that can hide a full-grown adult.
This cab-over tractor unit is much lower than usual, plus has a front mirror mounted just above the windscreen in the centre. The low cab height improves aerodynamics as well as dramatically reduces the blind spot at the front. This style of truck works well for applications where tight manoeuvring may be required due to the superior visibility around the cab

Above the cab

A blind spot exists above the cab and partially down the side of the truck or trailer which presents a risk to awnings and balconies, low branches and power lines, and doorways.

The blind spot above the cab, shown in green, often catches out new drivers trying to get into roller doors or under low-hanging barriers and branches

Behind the truck or trailer

The blind spot extends backwards in an elongated triangle depending on the angle of the mirrors. Any vehicle travelling in this blind spot is invisible to the driver.

Driver and passenger sides

A growing wedge extending backwards between 30-45 degrees (depending on the mirrors) hides vehicles in adjacent lanes, as shown in the image above.

The areas immediately next to the doors are blind spots that cyclists and motorcyclists don’t realise are extremely dangerous to sit in.

In a right-hand drive vehicle the driver has less of a blind spot next to the driver’s door, but a massive blind spot across beyond the passenger door, which would only be mitigated slightly if the door has extra glass panels

Bus or coach blind spots

As with the truck, a large triangular blind spot exists behind the bus, plus wedges extending left and right, and a wedge in front. The doors are usually glass so provide less of a blind spot than truck doors.

In a right-hand drive bus, there are blind spots caused by the A pillars and the mirrors.
Coach showing reversing camera mounted above the rear window
Bug antenna-style wing mirrors reduce blind spots by sitting further ahead of the bus. The tall front window also all-but eliminates the blind spot in front of the bus

How can blind spots be reduced for heavy vehicle drivers?

  • Convex mirror mounted above the passenger door facing down
  • Large side mirrors set fairly far forward with a convex lower mirror (but be wary of the blind spots the mirror itself creates)
  • Doors with lower glass panels
  • Manoeuvring cameras
  • Rear window in a day cab vs a solid rear wall like in a sleeper cab
  • Front-mounted convex mirror facing down towards the front bumper
Lower convex mirror, a large side mirror and a top convex mirror on the passenger side – about as much as you can do to reduce blind spots down the side of your truck

How are blind posts in heavy vehicles made worse?

  • Poor mirror placement and angling
  • Dirty mirrors
  • Dirty windows
  • Sunstrike
  • Passengers
  • Hanging items in the windscreen
  • Large or tall loads
  • Opaque window signage
driver training courses

Darren is a member of the Institute of Advanced Motorists and the NZ Motoring Writers' Guild

Tagged with: | Posted in Advice
When was the last time you checked your Road Code knowledge?

Try some tests for free!

Road Code car quiz

Road Code motorbike quiz

Road Code heavy vehicle quiz