For most roading projects, there is no substitute for ‘walking the block’. That is, getting out and looking first-hand at the forest area where new roads are being proposed. This will provide an overview of the site before any detailed planning work begins, especially where you’re unfamiliar with the block. The field overview assists with the interpretation of aerial photographs and maps that are used in the paper plan.
For smaller scale roading projects on known terrain, such as laying out a small spur road to a landing, the initial field work might be done at the same time the road grade is being laid out. In this situation, it is acceptable to lay out a proposed segment of road on the topo map as described in the next section.
As walking the block can be very time consuming, it is recommended to highlight areas of concern when assessing the terrain information to help focus the field visit. In addition to inspecting obvious features such as waterways, buildings and powerlines, the initial visit should also check for potential ‘problem’ features including:
- Rock bluffs and localised steep terrain
- Unstable soils and recent slips
- Environmentally sensitive areas such as wetlands
- Culturally sensitive areas such as pa, pits, middens and waahi tapu sites
- Utility services. For example, sewer, communications, water, power cables (both underground and overhead).
Where identified, these features should be recorded and preferably added to GIS data. If any of these features constitutes a hazard for road construction operations, there is also a legal requirement to both identify and transfer this information to the roading contractors. Recording this information on the detailed road plan map is the most acceptable way of transferring this information.
The local council or utility company will be able to provide information about utility services. A plan to manage safety and environmental risks can be developed and shared. Inadvertent contact or rupture is a significant risk to workers and a business. They have the potential to harm and/or damage the environment.