The overtaking road rules every NSW driver should know

Do you know the ‘Keep Left Unless Overtaking’ rule? 

The ‘Keep Left Unless Overtaking’ rule remains one of the most misunderstood road rules for motorists across Australia, despite applying on many of the roads drivers use every day.

If you’ve spent time on a busy motorway or highway, you’ve probably seen the frustration it can cause: drivers sitting in the right-hand lane well below the speed limit while traffic banks up behind them.

But the rule isn’t just about courtesy. Keeping left helps traffic flow more smoothly and reduces risky overtaking manoeuvres.

And while overtaking is a normal part of driving, it can also be one of the most dangerous and stressful manoeuvres motorists perform. Knowing when, where and how to overtake safely is an important driving skill. 

When can you drive in the right-hand lane?

The NSW Road Rules state that on multi-lane roads with a speed limit of more than 80km/h, motorists must not drive in the right-hand lane unless they are:

• Overtaking;
• Turning right or making a U-turn;
• Avoiding an obstacle;
• Driving in congested traffic;
• Driving in a special purpose lane or if there is a Left Lane Must Turn Left sign or a left traffic arrow and the driver is not turning left; or
• Otherwise instructed by road signs.

If a ‘Keep Left Unless Overtaking’ sign is displayed, the rule applies regardless of the speed limit. 

Despite this, many motorists either misunderstand the law or ignore it entirely, particularly on busy highways and freeways. 

Overtaking safely

Overtaking another vehicle always involves risk and requires extreme care. If you have any doubts, it’s best to wait until it is safe. 

Importantly, you must never exceed the speed limit to complete an overtaking manoeuvre – even if you are briefly entering a lane of oncoming traffic. 

While some drivers may feel tempted to accelerate beyond the limit to “get past quickly”, NSW road rule 20 is clear: a driver must not travel above the posted speed limit under any circumstances, including while overtaking. 

When overtaking, drivers must:

• Not go over the speed limit;
• Signal long enough to give sufficient warning to other road users;
• Check mirrors and blind spots;
• Give way to traffic in the lane they are moving into;
• Overtake on the right unless a vehicle is waiting to turn right, is stationary, or both vehicles are travelling in marked lanes;
• Not overtake or pass vehicles on pedestrian or school crossings; an
• Stay within their lane.

Drivers not overtaking should keep left and allow reasonable space for overtaking vehicles to pass and move safely back into the lane. 

What if another driver speeds up while you’re overtaking?

Many motorists will have experienced this frustrating scenario: a slower vehicle suddenly accelerates once an overtaking lane appears.

Not only is this dangerous, it’s also illegal.

In NSW, road rule 145 prohibits drivers from increasing speed while being overtaken. The offence carries a penalty of $423 and three demerit points.

If another vehicle speeds up while you are attempting to pass, the safest response is to remain calm, avoid speeding yourself and abandon the manoeuvre if necessary.

Can you overtake on the left?

Yes, although many drivers are surprised to learn there are situations where overtaking on the left is legal. 

In NSW, you may overtake on the left when:

• The vehicle ahead is stopped;
• The vehicle ahead is waiting to turn right or make a U-turn from the centre of the road; or
• You are travelling on a multi-lane road. 

As always, overtaking on either side should only be done when it is safe.  

Overtaking cyclists

Drivers are generally not permitted to cross or straddle solid dividing lines to overtake another vehicle. 

However, there is an important exception for cyclists. 

To safely pass a bicycle rider in NSW, drivers may:

• Drive to the right of the centre of the road;
• Cross or straddle dividing lines, including double unbroken centre lines; and
• Drive on painted islands and median strips. 

Drivers must still ensure they have a clear view of approaching traffic and can complete the manoeuvre safely. 

What's the penalty for not keeping left?

In NSW, failing to keep left unless overtaking can result in a fine of up to $423 and two demerit points. 

While it may seem like a minor offence, keeping left plays an important role in reducing congestion, minimising driver frustration and improving safety on high-speed roads. 

Read more: Nine tips to be a better driver