I was wondering if there was a minimum speed limit? I.e. if the speed limit is for example 60, is there a limit to how slow I can go before it counts as breaking the road rules? Is it relative to each speed limit or is there just one minimum?

If that is too broad, I live in Australia, so the rule(s) for Australia is enough.

  • In the USA some roads specify a minimum and others don't.
    – enderland
    Oct 18, 2015 at 14:41

3 Answers 3


In most Australian states, it is an offence to drive "abnormally slowly" in a way that unreasonably obstructs drivers or pedestrians. For example, in New South Wales:

  1. A driver must not unreasonably obstruct the path of another driver or a pedestrian

  2. For this rule, a driver does not unreasonably obstruct the path of another driver or a pedestrian only because:
    b. the driver is driving more slowly than other vehicles (unless the driver is driving abnormally slowly in the circumstances).
    Example of a driver driving abnormally slowly : 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.

  • So in the Australian rules there is no defined "slow speed limit"?
    – Ben
    Oct 18, 2015 at 22:44
  • 2
    No explicit lower speed limit, no. However you can be fined for obstructing traffic if you drive unreasonably slowly.
    – jimsug
    Oct 18, 2015 at 22:49

In my experience anytime somebody is going so slow as to cause a nuisance they are subject to a moving violation like "Impeding the Flow of Traffic."

In general statutes do not specify minimum speeds because the "safe and reasonable" speed for a road can vary (downward) with conditions.

I have occasionally seen posted minimums on highways in the U.S., but I have never found a special statute associated with those, so as far as I can tell they are merely encouragements to not impede the flow by driving too slowly.


In Belgium there is a minimal speed of 70 km/h on the highway. On other roads there isn't a minimum. If your vehicle can't reach that speed you aren't even allowed on the highway.

That actual text is as follows:

21.2 Behalve wanneer een lagere snelheid wordt opgelegd door het verkeersbord C43, mag geen enkele bestuurder op een autosnelweg met een lagere snelheid rijden dan 70 km per uur. Hij moet evenwel zijn snelheid regelen overeenkomstig de bepalingen van artikel 10.1.

or translated (my own):

21.2 Except when a lower speed is mandated by traffic C43, no driver on a highway is allowed to drive slower than 70 km/h. He has to regulate his speed in accordance to article 10.1.

Article 10.1 prohibits speeds that would hinder traffic or cause accidents.

However you will get run off the road if you drive slower than the speed limit.

Also in the practical portion of the driver's license test if you don't keep up with the flow of traffic you can be failed.

  • I trust that there's an exception somewhere that permits driving slower when conditions require it (eg. thick fog or a slippery road).
    – Mark
    Oct 19, 2015 at 5:36
  • Sounds like Article 10.1 "prohibits speeds that would hinder traffic or cause accidents", and that'd be both speeds too fast and slow.
    – jimsug
    Oct 19, 2015 at 5:40

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