In areas with steep topography, protect ridge lines and avoid large scars in the landscape by using underpasses or short tunnels.
Benefits and considerations
- Allows alignments to better respond to local landscape character
- May provide improve vertical alignment
- Retains connectivity at the surface above
- May involve complex engineering to be feasible in certain geology
- Treatments over a certain length will be treated as tunnels and need lighting, ventilation and additional ongoing management
Example
The Tintenbar to Ewingsdale upgrade on the Pacific Highway uses a short tunnel to avoid a cutting, keeping the natural ridge line intact. This has preserved the existing landscape character, views and connectivity along the ridge. The tunnel portals are well-designed, and the contours around the site have been carefully graded to integrate with the surrounding landscape.
Details
Location:
Pacific Highway, St Helena near Byron Bay
Agency responsible:
TfNSW
Application
| Main roads | Main streets | ||
|---|---|---|---|
| Motorway |  | Transit boulevard |  |
| Principal arterial | | High-activity high street | |
| Rural highway | | High-activity mall | |
| Rural link | | Transit street | |
| Connector avenue | | ||
| Transit way | | ||
| Local streets | Civic space | ||
|---|---|---|---|
| Connector street | | Destination high street | |
| Neighbourhood street | | Mall | |
| Yield street | | Civic lane | |
| Residential way | | Service lane | |
| Residential lane | | ||
| Street park | | ||
| Enterprise street | | ||
Legend
| Appropriate treatment |
 | Use with caution |
| Inappropriate treatment |
 | Not applicable |