Civil · 5 min read
Road and bridge design basics for private and council projects
Whether it is an estate road, a long rural driveway or a creek crossing, the same principles apply: get the alignment and levels right, size the pavement for the traffic and ground, and design crossings for the water they must carry.
Road design
Road design starts with alignment and levels, then pavement.
- Horizontal and vertical alignment to suit speed, sight distance and grades
- Cross-section with crossfall, kerb and table drains
- Pavement thickness from subgrade CBR and traffic loading
Bridges and culverts
Small crossings are often box or pipe culverts; longer spans need a bridge. Both are designed for hydraulics, traffic loading, foundations and scour, which is where geotechnical and structural input come together.
Frequently asked questions
- What do you need to start?
- A site survey, the expected traffic and, for crossings, catchment or flood information. We can arrange geotechnical testing if it is not available.
Need a road, driveway or crossing designed? Tell us about the site.
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