Car park line marking standards on the Sunshine Coast

The standards that apply

Car park design in Australia sits mainly under the AS 2890 series, and it is useful to know which part covers what.

• AS 2890.1 covers off-street car parking generally: bay dimensions, aisle widths, circulation, ramps and gradients for parking facilities.
• AS 2890.2 covers off-street commercial vehicle facilities, which is the one that matters for loading docks and truck movements.
• AS 2890.6 covers parking for people with disabilities.
• AS 1428.1 covers access and mobility, including the path of travel from a bay to a building.
• AS 1742 covers traffic control devices, and is relevant where a car park connects to a road or uses road-type signage and markings.

On top of those sits the planning approval for the property, which is where the required number of spaces usually comes from, and the National Construction Code, which brings in the accessible requirements.

The relationship that catches people out

The most common misunderstanding in car park layout is treating bay width, bay length and aisle width as three separate numbers you can choose independently. They are not.

A car parking in a bay needs room to swing in. If the aisle is generous, a shorter bay works. If the aisle is tight, the vehicle needs more room in the bay itself to complete the manoeuvre. The standard reflects this by relating the dimensions to each other rather than fixing them individually.

The practical consequence: you cannot squeeze in extra bays by narrowing everything proportionally. Doing so produces a car park where drivers need three attempts to park, which shows up as scraped cars, complaints and bays nobody uses.

It also means the honest answer to "how many bays will fit" is that it depends on what you are willing to give up, and that it needs measuring.

User classes

AS 2890.1 recognises that different car parks serve different users and that this changes the appropriate dimensions. A staff car park where the same people park every day, in the same bay, tolerates tighter dimensions than a shopping centre car park with unfamiliar drivers, trolleys, children and a high turnover.

So the right dimensions depend on what the car park is for. A contractor setting out a retail car park to staff car park dimensions is technically painting lines and practically creating a problem.

What else the standards cover

• Circulation and aisle widths, including one way and two way arrangements.
• Angle parking. Angled bays change the geometry considerably and suit one way circulation.
• Ramps and gradients, including transitions, which matter for ground clearance.
• Headroom in covered car parks.
• Sight lines at aisle intersections and at the exit to a road, which is where hatching often comes in.
• Pedestrian movement through the car park to the building.
• Small car and oversize bays, and the proportions in which they can be used.

Marking cannot change most of these. What marking does is implement a layout that respects them, which is why the set out conversation matters more than the paint conversation.

When compliance actually gets checked

Car park dimensions are typically assessed at development approval and at building approval, by the certifier and the council. After that, nobody re-inspects a car park as a matter of course.

What triggers a look is change. A refurbishment, a change of use, a sale, a lease negotiation, a refinance, an insurance review, or an access audit. That is when someone counts the bays, measures a few, and compares them to the approved plans.

The risk in a re-mark is quiet: if you change the layout to fit more bays in, or you lose bays to a new configuration, you may have moved away from what was approved without anyone noticing until it matters.