100 km/h speed limit sign
You must not drive faster than 100 km/h from this sign until the limit changes.
- Group
- Speed limit signs
- The group at a distance
- A number inside a red circle. On a zone sign the circle sits inside a larger plate carrying the times it applies. White ground, red ring, black numerals.
- Does this group carry the law
- Enforceable. The number is a maximum for good conditions.
- In the sign deck
- 3 questions ask about this sign
What to do when you see it
In the order you do it, from the moment the sign comes into view.
- Keep to 100 km/h or less, and reduce speed for wet roads, gravel edges or heavy vehicles.
- Hold a following gap of at least two seconds, which at this speed is around 55 m.
- Plan overtaking around marked overtaking lanes rather than around gaps in oncoming traffic.
Where you see it
On rural highways, on urban motorways, and on divided roads outside built up areas.
Across the states and territories
One hundred is the common open road limit in most jurisdictions, although the default limit outside a built up area with no sign is set by each state and territory and is not always the same number. Several jurisdictions also cap learner or provisional drivers below the posted limit, so the number on the sign is not always the number you are allowed to drive. Check your own agency's rules before assuming the sign applies to you.
Tell it apart from these
Both signs at the same size, next to each other, with the one line that separates them. These are the pairs people mix up under time pressure.
- 100 km/h speed limitthis page110 km/h speed limit
The higher number appears on the better roads, usually divided highways and motorways, so the change is a signal about the road as much as about speed.
110 km/h speed limit: You must not drive faster than 110 km/h, the highest limit posted on most Australian highways.
- 100 km/h speed limitthis pageFreeway begins
The freeway sign changes the rules about who may use the road. The speed sign changes only the number.
Freeway begins: Freeway rules start here, so no pedestrians, bicycles or learner restrictions that bar the freeway, and no stopping except in an emergency.
How the knowledge tests use it
Questions here usually test the learner or provisional cap rather than the posted number, because that cap is what a learner gets wrong.
A real question from the sign deckWhat does this sign mean?
This is a legal maximum for good conditions on that road. It applies from the sign until another speed limit sign appears.
Australian Road Rules rule 20, obeying the speed limit
Try it in a question
The sign tests draw the artwork above the question and ask what it means, which is closer to the way you meet a sign on the road than reading a page about it. They are original questions written for this site rather than an agency's published bank.
More speed limit signs
A number in a red circle on a white plate.