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 historic axis of Leura Mall, running along a dominant ridge line, runs perpendicular to the Great Western Highway. To upgrade the highway, while preserving the character of the Mall and its relationship to the surrounding landscape, we constructed a 125-m long underpass with a high-quality of architectural design. Access for all modes is via ramps which wrap neatly into a portal.
Details
Location:
Great Western Highway, Leura
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 |