A driveway long section is a side-on slice along the centreline, from street to garage. It shows height against distance — nothing about width, nothing about crossfall.
Read in the right order, it tells you whether a vehicle can travel this without touching.
What is on the drawing
| Item | What it tells you |
|---|---|
| Reduced levels (RL) | Height at each named point, against a datum |
| Chainage or distance | How far along the driveway each point sits |
| Zone lengths | How long each constant-grade run is |
| Gradients, as ratios | How steep each run is |
| Transition locations and lengths | Where the grade changes, and over what distance |
| Platform or slab level | The finished level the driveway has to arrive at |
An RL is a height relative to a datum, not a height above the ground. RL 10.000 at the boundary and RL 11.450 at the platform means a rise of 1.450 m — the absolute numbers don't matter, the difference does.
Read it in this order
- Both ends first. Boundary RL and garage slab RL. Their difference is the total rise or fall.
- Total length. Boundary to garage. Rise divided by length gives the average grade.
- The steepest zone. Not the average, which can comply while a middle zone doesn't.
- The length of that steep zone. Under QDC NMP 1.1 the run steeper than 1 in 5 has to stay within 6 m to use the 1 in 4 concession.
- Both transitions. At each end of the steep section, at least 1 m at no steeper than 1 in 8.
- The arrival. Whether the last zone meets the slab level, and at what grade.
Steps 3 to 5 are where drawings normally fail.
Ratios, and which way they point
A gradient written 1:6 means one unit of rise for six of horizontal distance, so a bigger second number is flatter. 1:20 is near level, and 1:4 is the steepest a Queensland residential driveway may reach.
Up or down comes from the profile line or an arrow, not from the ratio. Reading it backwards is expensive, because a driveway drawn falling when the site rises can't be built.
Conversions between ratios, percentages and degrees are in how steep can a driveway be.
A published example
Section B of IPWEA standard drawing RS-050 (the sheet used by several South East Queensland councils) is a long section worth reading. It dimensions the vehicle crossing in segments, not a single grade, with levels tabulated at set distances so nothing has to be scaled. Detail in the Gold Coast article.
What gets a drawing sent back
- Grades shown but no zone lengths, so the 6 m steep-run limit can't be checked
- A transition marked but not dimensioned
- Levels at the ends only, with the middle left to be scaled off the page
- No statement of which document the design follows (see which one applies)
- A crossover profile that stops at the boundary, when the council's drawing governs what's in front of it
Disclaimer
General information, not advice. References to QDC NMP 1.1 summarise it as published rather than reproducing it, and it is a non-mandatory part of the Queensland Development Code. Councils and individual approvals may require something different. Confirm what applies with the relevant council or a qualified certifier.
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