Driveway design

A steep site doesn't have to mean a rejected DA.

Driveway design confirms your entry and exit points are safe and compliant for every vehicle expected to use them — and gradient is where most sloped-site designs fail, usually because the transitions weren't calculated properly.

Core gradient rules (AS 2890.1)

  • Maximum grade within the property: 1 in 4 (25%)

  • Maximum grade at the property line or footpath crossing: 1 in 20 (5%), extending 6m into the site to protect sightlines

  • Transitions required wherever a grade change exceeds 1 in 8 (12.5%) — minimum 2m long, at roughly half the difference between the two grades, preventing underside scraping at summits and sags

  • Design vehicles modelled at 120mm ground clearance to verify the full swept path stays clear

Engineering for steep sites

  • Switchbackshorizontal curves that extend travel distance to bring the effective grade back under 1 in 4

  • Flat landing zonesrequired top and bottom, maximum 1 in 20, giving vehicles a safe pause point before entering traffic

  • Swept path verificationconfirms longer vehicles clear the inner kerb and stay off opposing lanes on curved layouts

  • Surface selectionsolid, textured surfaces on steeper grades for wet-weather traction; loose gravel isn't suitable

What council wants to see

Longitudinal sections showing existing versus proposed levels, cross-sections at the property boundary and garage entry, and formal certification confirming ground clearance holds throughout.

FAQ

Common questions

What's the steepest a driveway can be?

1 in 4 (25%) within the property, dropping to 1 in 20 (5%) for the first 6m at the street.

How do you stop vehicles scraping on a steep driveway?

Transition grades — at least 2m long, roughly half the main slope — at every point where the grade change exceeds 1 in 8.

Does this apply to single residential driveways too?

Yes — AS 2890.1 governs all off-street driveway design, including houses on steep or constrained sites.

What if full compliance genuinely isn't achievable on my site?

Councils can accept a “Performance Solution” — a more detailed engineering case proving an alternative design is still safe and functional.

Parking, access and swept paths

Send us the drawings. We'll tell you what you need.


What to send
1. Site address
2. Plans, if they exist
3. A description of the works
Sightline Traffic EngineersContact
1800 008 782
plans@sightlinetraffic.com.au
9 Epic Pl, Villawood NSW
Mon–Fri, 8am–5pm
ABN 16 699 960 668