Is it illegal to drive too slowly?

Is it against the law to drive below the speed limit? Well, that depends...

Frustrated Driver Jpg

There are few things more frustrating when driving than being caught behind someone who, for reasons known only to them, has decided to travel even just 10km/h below the speed limit.

Which is why Twitter erupted with joy earlier this year when the West Australian Police posted a picture of an infringement notice given to the driver of a Toyota Landcruiser ute spotted driving well below the limit on the Mitchell Freeway.

The infringement notice points out the driver of the Toyota Landcruiser ute was travelling “21km/h or more under the speed limit”, which in that state is actually a specific offence.

But in most jurisdictions around Australia there isn’t a particular law pertaining to driving too slow, nor are there any minimum speed thresholds at which you’re allowed to travel.

However, driving significantly below the speed limit can be deemed an offence under Australian Road Rule 125 that states: “A driver must not unreasonably obstruct the path of another driver or a pedestrian” with the following provisos:

“For this rule, a driver does not unreasonably obstruct the path of another driver or a pedestrian only because:

  1. The driver is stopped in traffic; or 
  2. The driver is driving more slowly than other vehicles (unless the driver is driving abnormally slowly in the circumstances). 

It then gives the following example.

“A driver driving at a speed of 20 kilometres per hour on a length of road to which a speed limit of 80 kilometres per hour applies when there is no reason for the driver to drive at that speed on the length of road.” 

WA traffic police

So while it’s clear that driving too slow and obstructing traffic behind you is an office, the word “unreasonable” allows for discretion for drivers who may have a reason to be driving slowly such as inclement weather, driving past an accident scene, animals on the road or mechanical issues where it’s unsafe to stop.

The law can also be used against drivers who hog the right lane on a freeway even if they’re travelling within a few km/h below the speed limit. But it also allows for someone to drive as slowly as they want if they’re not obstructing traffic.

“If you are going 50km/h down the Monash Freeway at 1am with no cars on the road it’s not a drama,” Victoria Police Highway Patrol inspector Simon Humphrey told News Ltd. “But if you are doing that speed at 7am, in the right-hand lane during peak hour, it might be a problem.

“It’s about common sense. It’s about obstruction rather than speed.

So, in short, use common sense and think of other drivers. And remember, even if someone is breaking Rule 125, it doesn’t excuse you from breaking Rule 126 – “A driver must drive a sufficient distance behind a vehicle travelling in front of the driver so the driver can, if necessary, stop safely to avoid a collision with the vehicle.”


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