The Queensland Department of Transport and Main Roads has confused drivers again with a quiz about a road rule on social media.

The department posed the age-old question as to how much space should be left between two cars.

“You know your road rules, and now’s your chance to prove it,” the department wrote.

“The weather conditions are fine and there’s no traffic on this road – so what’s the minimum safe following distance the blue car should be maintaining?”

Many said that the blue car was "travelling too close regardless of weather conditions" and others said that the "minimum safe following distance was two seconds" or "one car length behind the car in front".

“As a rule of thumb 2 seconds. But it also depends on the speed you are travelling,” one user wrote on Facebook.

“The faster the speed the greater the distance.”

Others were quick to disagree, saying that the orange car was "going too slow for the speed you're wanting to go".

“No other traffic – then overtake,” another user wrote.

“Teach people to not drive slow in the right-hand lane on freeways. Every freaking day on the Centenary Highway it’s the same thing,” commented another.

“According to the truck driver that was behind me on the Bruce Highway last night it’s OK to have 20+ tonne only 2ft behind my car,” commented another.

Some used the question to air their grievances against the Department of Transport, saying “Queensland Transport drivers tailgate all the time. So I guess the answer is ‘As close as you want’.”

The answer is at least two seconds behind the vehicle in front of you.

“Following another vehicle too closely is what we call ‘tailgating’ – and if you’re tailgating it can make it a lot harder to stop safely in time to avoid a crash,” the Department wrote.

“In ideal conditions, you should leave *at least 2 seconds* behind the vehicle in front of you.

“If the conditions are poor or you’re towing a trailer or caravan, you should increase your following distance.”