THE State's peak motoring body has put drivers on notice to refresh their knowledge of the road rules, releasing five of the most commonly forgotten laws.

RACQ's Lauren Ritchie said ignorance wasn't a valid excuse if caught out.

"Some people may think a lack of knowledge of a particular road rule might be enough to get them out of a ticket, but it's not," Ms Ritchie said.

"It's the driver's responsibility to know the rules before getting behind the wheel."

Ms Ritchie said the Queensland road rules were regularly updated, making it important to stay up to date with the latest changes.

"Chances are the legislation has changed slightly since most people sat their driving exam, so staying across new laws is vital," she said.

"While some drivers may not agree with all of the road rules, they're in place for a reason and that's to keep all road users safe."

The five road rules you didn't know you were breaking, were:

• Your car must be locked, key removed from ignition and handbrake on if the driver is more than three metres away from their car
   
• It's against the law for your number plate light to be out, as your registration plate needs to be clearly visible at all times
   
• You can't leave your car locked and unattended with the window open any wider than five centimetres
   
• It's an offence to use your horn unnecessarily, like saying goodbye or getting frustrated at other motorists
   
• Drivers only need to keep left unless overtaking when roads have a speed limit of more than 80km/hr.