Author: Petra Stock
Depending on the specific requirements of the local authority, you may need to do a traffic management plan (or transport study) as part of your development application for a proposed wind farm. This article describes how to put one together.
What is a traffic management plan?
A traffic management plan looks at the types of vehicles you'll use during the construction, operation and eventual decommissioning of your proposed wind farm. It also identifies suitable routes to the site from the delivery point or place of manufacture for each wind farm component, and involves consultation with local and state road authorities. Importantly, the study will list ways to minimise any impact on the road network.
You would normally complete this type of study to show how you'll manage the traffic impacts on the local and regional road network. Traffic and transport issues rarely influence the wind farm layout or pose a serious threat to planning approval.
Scoping the job for a consultant
When you engage a consultant to write a traffic management plan, it's worth following the advice in the Engaging specialists for environmental & technical studies article. Essentially, the article suggests you write a tight scope and get multiple quotes for the job.
Your scope should generally include:
- a detailed description of your wind farm including turbine types or dimensions and their locations. If this is still unknown, it's best to include a 'wind farm envelope' — the largest area in which turbines could be sited
- the reason you're having the report written (for example, to satisfy planning conditions)
- who will need to read the report
- what you expect too see in the report (see 'what to expect' below).
Information a consultant will need
The inputs to a traffic management plan typically include:
- a standard project description, including type and number of turbines, and the location of the site
- GPS coordinates of the site boundary
- which ports you anticipate turbine components being delivered to
- the location of any local manufacturers, for example turbine tower manufacturers
- how turbine components will be transported to the site, for example one tower section per truck and two blades per truck
- a breakdown of the types of vehicles required during construction and operation, mainly the over-size and heavy vehicles used during construction.
What to expect in the consultant report
A good consultant report will be a standalone document. This means it will have thorough explanations, so even someone who's not an expert in the field can interpret it. It will also have appendices, which list all the input data including assumptions and calculations of traffic numbers.
A standard traffic management plan for a proposed wind farm usually includes:
- a review of local, state and federal planning policies and guidelines relevant to traffic and transport issues
- consultation with the local and state road authorities about suitable routes to the site from key ports, places of manufacture and warehouses, and any upgrades required
- a description of the local and regional road network surrounding the site, including characteristics of proposed routes to the site (traffic volumes, whether the road is sealed or unsealed, road width, presence of road reserves, and any required upgrading)
- a description of the routes and hours of operation for any local school bus services
- a description of activities during construction, operation and decommissioning that will generate traffic, and calculations on the number and types of vehicles expected during each phase. The wind farm developer usually gives this information to the consultant
- a summary of existing traffic flows (number of cars and trucks each day) and conditions on key routes to the site
- a summary of road accident statistics for proposed routes to the site, highlighting any potential safety issues or accident black spots
- an assessment of the additional impact on the road network as a result of the traffic generated during the construction and operation phases
- a description of traffic impacts
- a list of proposed mitigation and management measures.
Typical mitigation measures
A traffic management plan usually makes recommendations for suitable transport routes and for managing the impacts of traffic during construction. These recommendations usually become part of a broader environmental management plan for the site.
Measures usually include:
- any relevant codes or guidelines that must be adhered to
- any upgrades required to the road network
- speed restrictions
- any approvals required for trenching through roads or road reserves (if underground cabling is proposed)
- permits and conditions for heavy vehicles and oversized trucks
- restrictions relating to school bus operation, for example construction traffic may be limited during school bus hours
- dust management
- traffic management plans.
Implications for wind farm layout
Traffic and transport considerations rarely affect wind farm layout, providing there is an available route to the site for transporting the wind turbine components.