On main roads, keep the vertical curves located within the horizontal curves – never start a horizontal curve beyond the crest of a vertical curve.
Benefits
- Allows a road to respond to its context more successfully
- Provides a more enjoyable travel experience
Considerations
- May be undesirable or impossible to achieve where there is prominent built element nearby
Reference
Austroads Guide
Guide to Road Design Part 3: Geometric Design, Section 6
Examples
The alignment of the Pacific Highway near Macksville smoothly guides people along it, with a harmonious relationship between the lateral curves on approach to the bridge and the crest across the Nambucca River.
Location:
Pacific Highway, Macksville near Old Coast Road
Agency responsible:
TfNSW
Conversely, the Princes Highway at Pambula displays a poor relationship between vertical and horizontal alignments. A sharp left-hand deviation is awkward and out of keeping with the broader alignment, and a slight dip creates an uncomfortable experience for people navigating a bend. The visual expression of this alignment is also awkward.
Location:
Princes Highway, Pambula
Agency responsible:
TfNSW
Application
| Local streets | Main streets | ||
|---|---|---|---|
| Residential lane |  | Destination high street | |
| Residential way | | Transit street | |
| Yield street | | Connector avenue | |
| Neighbourhood street | | Arterial high street | |
| Connector street | | Transit arterial | |
| Urban centre street | | ||
| Enterprise street | | ||
| Main roads | Civic spaces | ||
|---|---|---|---|
| Transit only corridor | | Civic high street | |
| Rural link |  | Transit mall | |
| Rural highway | | Civic lane | |
| Secondary arterial |  | Service lane | |
| Principal arterial | | ||
| Motorway | | ||
Legend
| Appropriate treatment |
| Use with caution |
 | Inappropriate treatment |
| Not applicable |