Is it illegal to always drive in the right-hand lane?

It means what it says. If you're driving on a road with more than one lane, you should keep left unless you're overtaking. But there are differences in the way the rule is implemented and interpreted across the country.

Generally speaking, if you're driving on a multi-lane road with a speed limit of less than 80km/h (think of those inner-city arterials that always seem to be crawling at crabs' pace), you can drive in whatever lane you want.

But if the road is a motorway, highway or freeway with a higher speed limit, it's best not to populate the right lane permanently, as you could face fines and demerit points if you're not overtaking other road users.

Here's a rundown of the rules across the country:

In NSW, if you're driving on a road that has a sign-posted speed limit above 80km/h (so, in 90km/h zones, or roads with speed limits higher than that) you have to keep left unless you're overtaking someone.

That's the general rule, but there are some exceptions:

NSW road rules state: "You must not drive in the right lane, unless you're overtaking, turning right, making a U-turn, not turning left and there's a 'Left lane must turn left' sign or traffic lights with a left arrow signal, avoiding an obstruction, driving in traffic that's stopped or travelling slowly in the left lane, driving a bus or a truck and the right lane is for buses or trucks only, overtaking a slow vehicle making a left turn."

Situations where you need to overtake using the left lane include when the vehicle you're overtaking is: "waiting to turn right or make a U-turn from the centre of the road; stopped; travelling on a multi-lane road".

In some instances you are allowed to use the left lane if there's stopped traffic in the right lane, and you're allowed to: cross the outer edge lines (for a maximum 100m), drive in a bus lane, transit lane or truck lane (for a maximum 100m), or drive in a bicycle lane or tram lane (for a maximum 50m).

Get caught doing the wrong thing and the fine is $349 and two demerit points.

In QLD, the rules are clear. "On single-lane roads, you must stay as close as practical to the left side of the road."

But if the road has multiple lanes and if the speed limit is 90km/h or above, or if the roadway has signage stating 'Keep Left Unless Overtaking', then you must not use the right lane unless you are: overtaking; turning right; making a U-turn; avoiding an obstruction; driving in congested traffic; or using a special purpose lane that you are allowed to be in.

And in news that will upset anyone who believes in proper lane etiquette (here's looking at you, Germany) it's legal for drivers to "overtake on the left on all multi-lane roads".

You can still be fined for sticking in the right lane if you're not doing any of the above-mentioned actions. The penalty is a $123 fine and two demerit points.

The rules for Victoria state that drivers on "any multi-lane road with a speed limit over 80km/h… must keep out of the right lane".

But as with the other states, there are some exceptions, such as if you are overtaking or turning right, or all lanes are congested. Further, "if the right lane is a transit lane, this rule applies to the lane immediately to the left of the transit lane".

Note the wording of the rule, though. If you read between the lines (or should that be lanes?) it essentially means the far-right lane is off limits unless overtaking.

If you're on one of the six-lane freeways, the rule means you can use lanes one through five as you wish.

Get caught being naughty, and you could be up for two demerits and a few hundred bucks in fines.

The SA police prefer if you keep to the "far left side of the road" in multi-lane situations, lest you face a $355 fine and two demerits.

One thing that's different about SA is that roads with speed limits at 80km/h or more don't need to have "keep left" signage present.

It's understood, if the speed limit is high and there's more than one lane available to be driven in, that road users should keep in the far-left lane and reserve the right lanes for overtaking only.

The big state has pretty similar rules to the rest of the nation. If the speed limit is 90km/h or more, you need to keep left. Under 90km/h, you only need to do so if there's signage stating as much.

As with other states, you're allowed to disregard the keep left signs if you're overtaking, making a U-turn, avoiding an obstruction, if the left lane is a turning lane and you're not turning, or if the left lane is a special use lane (bus, slow vehicle turnout lane etc).

Further, if other lanes are congested with traffic, you can stick in the right.

The fine is teeny, at $50, but it still has two demerit points attached to it.

In the NT the rules state that if the road has more than one lane and a speed limit of more than 80km/h, or it has a 'keep left unless overtaking' sign, then you must keep to the left side of the road.

And in a nice touch, NT also reminds road users that, when they are being overtaken, they must not increase their speed, must also keep left and allow enough space for the overtaking vehicle, and also stay within their lane.

No demerit points or fines for this doing the wrong thing, and get this: Northern Territory doesn't do double demerits, either!

In the Australian Capital Territory – aka, the land of the roundabout – if you drive in the right lane and you're not overtaking (and the road's speed limit is over 80km/h) you could be fined $316 and smacked with two demerit points.

The expectation is that, in Tassie, if the speed limit is above 80km/h, you should keep to the left unless you're overtaking – whether there are signs to state it, or not.

Failure to follow the rule could result in a $146.25 fine, and two demerit points.

And because cyclists are road users, too, if you're riding your bike in the right lane on a road with 'keep left' signs, you could face a $130 fine.

Not intended as legal advice. Check with the relevant roads authority in your state or territory.

Content originally sourced from: CarExpert.com.au