21 Aug 2018Building a New Road, Concept to Construction
Most of us give the roads we drive on little thought, but each one has followed a rigorous process to ensure they are safe for us to travel
on. So what does the construction of a new road involve? How does a proposed new road go from planning and design, to construction and opening? Here's a guide to the basics:
STAGE ONE: SITE INVESTIGATION
The first step is to work out whether a new road is feasible. To determine this, a site investigation is carried out to assess existing land use and the nature of what lies beneath the proposed new road.
Information gathered from historical records and a range of experts help to determine what is under the land and whether any significant fault lines are present. Once all the available information is gathered, further investigations are undertaken as necessary. For example, a site may require an archaeological excavation to recover historical and cultural artefacts.
A thorough assessment is conducted to ensure that the site can accommodate a new road. This also identifies any problems, the need for alternative routes, the costs involved and the stability of the ground.
STAGE TWO: PRELIMINARY DESIGN
Once site investigation has been completed, a team of experts are tasked with the preliminary design. This stage focuses on the location of the road, the benefits to the existing road network and any environmental impact.
In New Zealand, all new roads must adhere to the Resource Management Act. This piece of legislation governs the management of natural and physical resources such as land, air and water. The Act is responsible for protecting the environment and ensuring that any new project is sustainable.
The development of a new road must therefore pay significant attention to any potential impacts on natural resources. A large part of the preliminary design outlines any environmental impacts and the ways in which these will be managed. Ideally, a new road should work with the natural environment and be designed with sustainability in mind.
The preliminary design must also detail storm water drainage and consider the need for public transport access, cycle ways and paths.
All risks and benefits of building on the proposed site must be detailed. Alternative routes may also be identified and included if planners foresee any potential problems with the preferred route.
STAGE THREE: DESIGNATION AND CONSENT
When the preliminary design work is completed, plans are submitted to the relevant authorities
for consideration. Key stakeholders, such as
residents, iwi and local boards are consulted on the development before the new road gets the go ahead.
STAGE FOUR: PRE-CONSTRUCTION BEGINS
Pre-construction work is one of the most fundamental components of building a new road. Much like a house needs solid foundations, so too does a road.
During pre-construction, the site is prepared for the final construction stage. Excavation of the site can include both the removal of dirt and the filling of any areas that need to be built up and leveled. Roads require a substantial foundation, which is why the base layers are as important as the finished surface.
During pre-construction, storm water drainage is installed and any utility works are undertaken.
Upon completion, all pre-construction work must undergo strict inspections to ensure the highest possible safety standards have been adhered to, and to identify any potential problems.
STAGE FIVE: CONSTRUCTION AND SAFETY AUDIT
Road surfacing, marking, pathways and landscaping are all part of the final construction stage. In New Zealand, the type of surface laid depends upon various factors such as noise reduction, consideration of using recycled materials and the best surfacing for the type of road. Other considerations may include the volume of traffic on the surface and how much maintenance will be required.
Glenvar Ridge Road is a new road, currently in the final stages of construction, that will connect the existing transport network with the urban development in
Long Bay. This road has been developed by Todd Property Group in collaboration with local authorities to provide a direct route into and out of the area. “The bulk of the Glenvar Ridge Road surface is a stabilising base layer of lime and cement, mixed with natural clay soil, which is around 300mm deep. The middle layer is composed of lime and coarse materials up to 500mm deep. Approximately 50mm of asphalt will form the final top surface,” said Paul Armstrong, Todd Property Development Manager.
During the final construction of a new road everything must be thoroughly tested; from the shape of the road to its strength, every detail must meet strict criteria. When construction is complete, the road must pass a safety audit before it is finally opened to the public.
PROPOSED NAMES for a new road are often submitted early in the planning process. Submitting a list of suggested names means it’s more likely that one or more will be approved
and developers typically allow plenty of time for consideration by relevant stakeholders.
The naming of a road must adhere to an extensive list of rules. For example, in Auckland, road names must be easy to pronounce, spell and write. They are limited to three words (or 25 characters), except in the case of Te Reo names.
A road name must not be considered offensive, racist, derogatory or demeaning, even when translated into another language. Some roads, such as those with five or less addresses, do not need to be named if numbering can be continued from an adjoining road.
Certain punctuation cannot be used in a road name such as a full stop, comma, colon, semi-colon, quotation marks, hyphens or others. Only characters from a standard alphabet can be used, although macrons can be used for Maori names.
Road-naming reports are prepared and submitted to local boards for consideration.
After discussion and consultation, the relevant authority will make a final decision.