Many renewable energy projects are considered major projects due to their high value and often lengthy construction periods which can occur over several years. This means a comprehensive Environmental Impact Statement is usually required, which our Traffic Impact Assessment (TIA) would form a key part of amongst other disciplines including ecology, heritage, noise and more. Key components of the traffic assessment process are outlined below.
Background Review and Data Collection
The first phase of the project involves gathering all of the necessary data to carry out a robust assessment. This may include kick-off meetings with the project team, arranging traffic counts/surveys and helping our clients work out the traffic generation and vehicle types that would be required for the construction process. We have developed a unique spreadsheet tool for our clients to assist with calculating the light and heavy vehicle volumes based on key details of the project such as the workforce size, construction duration, equipment/materials required for the project and any use of accommodations camps, shuttle buses and/or carpooling.
Assessment of the Existing Transport Environment
We carry out a detailed review of the existing road environment near the project area to establish the current operating conditions and identify any existing risks and constraints. Our scope is comprehensive and generally includes review of the following:
- Existing land use and access arrangements
- Road geometry
- Traffic volumes
- Operating speeds
- Any planned road upgrades or events
- Public transport and school bus services
- Approved access networks for restricted vehicles such as B-Doubles, Class 1 oversize/overmass vehicles and Special Purpose Vehicles
- Road safety assessment based on a review of the recorded crash history over the most recent 5-year period.
Summary of the Project Scope and Construction Details
This section of our report provides a summary of the proposed infrastructure to be delivered as part of the project. It also includes relevant details of the construction methodology and timeframes including:
- Construction schedule outlining the various stages and expected peak times of on-site activity
- Workforce details including potential towns/cities where personnel would reside
- Details of locations where materials and equipment would be sourced from including the arrival ports for any incoming deliveries.
Traffic Assessment
A key component of our TIA reports is the assessment of traffic which would be generated by the project on a day-to-day basis. The assessment for renewable energy projects focuses primarily on the construction phase, which is when the largest traffic impacts are expected, however a review is also undertaken for the traffic generation requirements during operation and decommissioning.
The construction phase of a renewable energy project will typically generate a range of vehicle types including light vehicles, rigid trucks, truck and dog configurations, semitrailers, B-Doubles and certain oversize/overmass configurations which are able to operate on various sections of the road network. Any oversize/overmass vehicles which exceed certain dimension or weight limits and are required to travel under escort are carefully considered in a separate part of the assessment as their movements are often considered to be ‘high-risk’ by the road authorities and may require road upgrades or specific traffic management measures.
The traffic assessment typically includes a comprehensive review of the following items to determine whether the project traffic is able to be suitably accommodated on the road network:
- The vehicle types and associated traffic volumes expected during peak and average periods of construction activity
- Traffic distributions for the arrival and departure of each vehicle type
- Any potential cumulative traffic impacts associated with other developments which may be currently operating or planned in the area
- Traffic modelling using the SIDRA intersection software to review any impacts to key intersections if required
- Mid-block traffic volumes which would be generated across the road network.
Route Assessment for Heavy Vehicles and High-Risk Oversize/Overmass Configurations
We undertake a detailed review of the access routes for heavy vehicles and high-risk oversize/overmass configurations to ensure the proposed roads are suitable to accommodate these types of vehicles which may be subject to various travel restrictions, road upgrades or traffic management measures. We are experienced in preparing detailed routes assessments for solar and BESS projects, which would be typically undertaken for the transformer transport vehicle as the largest configuration expected to access the site. We typically recommend assessment of wind turbine components is undertaken by a specialised transportation company for a range of reasons as outlined in our article on traffic engineering for wind farm projects.
The route assessment considers the existing road infrastructure and any key constraints along the route to identify the extent of any road upgrades or mitigation measures required. It generally includes review of:
- Geometric ‘pinch points’ along the route including any turning movements at intersections or tight curves.
- Rest areas available for fatigue management, passing opportunities or emergency protocols.
- Identification of structures such as bridges and culverts along the route which may require further assessment of structural capacity or load limits.
- Height clearances at underpasses or overhead obstructions along the route.
- Railway level crossings and any specific requirements that may be imposed by the rail authorities.
Review of Site Access Arrangements and State/Regional Road Intersections
Our assessment considers whether any turn treatments should be provided along the road network or at the site access locations based on the expected volume of traffic and in accordance with the Austroads Guide to Traffic Management. Similarly we review the available sight distances at each relevant location to ensure vehicles are able to safely enter/exit the site area as well as any key State/Regional Road intersections. These are important safety considerations to reduce the risks associated with higher levels of traffic operating on the road network including heavy vehicles.
Preparation of a Draft Traffic Management Plan (TMP)
We will either prepare a draft TMP or outline recommended measures to be included within the document which would set out a range of operational measures to effectively manage the vehicle movements associated with the project. The TMP is an important part of ensuring the safety and capacity of the road network is maintained.
Summary of Mitigation Measures and Road Upgrades
Our reports provide a concise summary of the proposed mitigation measures and road upgrades which will often inform the consent conditions for the project.
The Traffic Impact Assessment process for renewable energy projects is comprehensive and requires a specialised approach as well as regular consultation with the road authorities. Furthermore, these projects often involve a high proportion of heavy vehicles including oversize/overmass configurations to deliver materials and equipment to the project areas.
We have extensive experience preparing these assessments and pride ourselves on our specialist expertise in this area and ability to work collaboratively with the broader project teams. Please feel free to contact us if you require a Traffic Impact Assessment or for any specific queries or general advice in relation to renewable energy projects.
