6 Conclusions and recommendations
6.1 Traffic impacts of unconventional oil and gas development
The development of Scotland's unconventional oil and gas resources would result in associated road traffic movements. Road transportation would be needed for movement of plant, equipment, materials and waste.
Estimates were made of potential traffic movements per well pad, as follows:
Table 12: Estimated traffic movements for individual well pads over the well lifetime
|Scenario||Vehicle type||No re-fracturing, no water transport||With re-fracturing, no water transport||No re-fracturing, with water transport||With re-fracturing, with water transport||Coal-bed methane|
|Total over 20 year
|Total over 12 year period approximately|
Note: "Light" vehicles include motorcycles and all two-axle, four-tyre vehicles - that is, light trucks as well as cars.
The peak traffic movements were estimated to be up to 430 movements per week, and traffic movements at an individual site could be sustained at around 190 per week for a period of approximately 2 years under the Central scenario. For context, typical traffic flows associated with other traffic-generating development include:
- Food superstore: Approximately 60,000 two-way vehicle trips
per week (most
would be light vehicles)
- Warehouse / distribution centre Approximately 5,000 two-way HGV movements per week
- Windfarm at construction stage Approximately 800-1,000 two-way movements per week
The potential impact of wide-scale development of unconventional oil and gas resources in Scotland was considered. At a regional or national scale, traffic movements would have effects on aspects such as vehicle exhaust emissions, highway damage and accident risk, as with any other industry sector.
It was found that the range of UOG development scenarios considered could give rise to between 210 and 1,670 traffic movements per week on average across the country as a whole, with a further 99 movements associated with the coal bed methane scenario. For context, approximately 4.3 million trips were made by cars and goods vehicles in Scotland each weekday in 2012.
It is concluded that, if the moratorium on UGO development in Scotland is lifted, the additional traffic movements associated with onshore oil and gas resources would be unlikely to be significant or detectable at a regional or national scale, in view of the much greater numbers of traffic movements resulting from other activities. Hence, as with any comparable industry sector, traffic associated with UOG development would have a slight adverse influence on some Scottish National Indicators, principally the following:
- Reduce traffic congestion
- Reduce deaths on Scotland's roads
- Improve access to local greenspace
It is concluded that the contribution of UOG development to these indicators would be slight and comparable to many other industry sectors and activities. Hence, it is considered that no significant weight should be given to the impacts of traffic associated with UOG at a national or regional level.
Consequently, the key focus for consideration of potential community impacts of UOG development should be the assessment and management of potential impacts on communities local to development sites. The main factor affecting traffic flows to and from a well pad site is the requirement for transportation of clean and waste water. If the transportation of water by road can be avoided ( e.g. by use of pipelines and/or by re-using wastewater), traffic impacts can be significantly reduced.
6.2 Potential community impacts from transportation
Road traffic impacts are one of the aspects of UOG development of greatest concern both to the general public and professional analysts. These impacts arise principally from increases in heavy goods vehicle movements on potentially unsuitable roads. These movements would take place over a relatively limited period for an individual well, but may occur over a much longer period for development of a multi-well pad, and in particular in situations where a shale gas field is being developed.
Managing the road traffic impacts of new development is a well-established discipline with project developers and regulatory authorities. UOG development is different from other more familiar activities, in that development would take place at locations which would be determined by a broad range of factors, including, but not limited to, the desirability of minimising traffic impacts. The areas potentially prospective for UOG development include much of the Central Belt of Scotland, and cover rural, suburban and urban areas (see Figure 1 and Figure 2).
Consequently, UOG development could potentially take place in rural, suburban or urban settings. These would pose different challenges in respect of the management of transportation impacts. These challenges would focus on the potential for traffic movements to take place along potentially unsuitable routes.
6.2.1 Site typology
A UOG site may comprise a well pad, compressor station, water treatment works, or other infrastructure. An outline site typology is provided below, which may assist in identifying and managing potential impacts at a strategic or site-specific level.
- Site with good highway links: It may be possible to locate a UOG site at a point with good connections to the main road network. In this case, there are unlikely to be significant community impacts from road traffic, although it would be important to ensure that this is given full consideration through the planning process.
- Industrial site: A UOG site in an industrial setting is likely to have good connections to the main road network. Additionally, neighbouring land uses are likely to be industrial in nature, and hence would typically have low sensitivity to traffic impacts. In this case, there are unlikely to be significant community impacts from road traffic, although it would be important to ensure that this is given full consideration through the planning process.
- Rural site: A rural UOG site could potentially be located at some distance from the main road network. This could potentially require vehicles accessing the site to use unclassified roads which may be unsuitable in view of the proximity to sensitive properties, road surface, road width, poor visibility, or potential for effects on natural ecosystems. Such impacts should be carefully considered through the planning process.
- Urban/suburban site: An urban or suburban UOG site could potentially be located at some distance from the main road network. This could potentially require vehicles accessing the site to use roads which may be unsuitable in view of the proximity to sensitive properties which may be numerous; presence of pedestrians/cyclists; road surface; road width; or poor visibility. Such impacts should be carefully considered through the planning process.
Additionally, a subcategory of each of the above site categories may be considered:
Subcategory: Site with reduced water transport
requirement. Water transportation accounts for a
substantial proportion of heavy goods vehicle movements to and
from a well pad site. A site in any of the above categories with
the opportunity to reduce water transport would be more
favourable from the perspective of managing transportation
impacts. This could be achieved in a number of ways:
- Mains water connection
- Piped supply of fresh water and/or removal of waste water
- Complete or partial re-use of waste water on site
The following sections summarise the potential community impacts of traffic associated with UOG development, and outline how these potential impacts would be managed.
6.2.2 Potential for accelerated road surface degradation
UOG development presents a risk of damage to road surfaces and the underlying road structure through additional loading by heavy vehicle movements. This impact can be mitigated through cost recovery through taxes or fees; through policies designed to decrease damage to roadways such as truck weight limits; and/or altering infrastructure to make it more resilient. Maintenance agreements are currently used in the United Kingdom for both UOG and other types of process that generate significant volumes of HGV traffic, and may involve before and after condition surveys, the carrying out of specified remedial works, and/or making a payment under a Section 96 agreement to recover the cost of road repairs.
6.2.3 Risk of increased accidents
The evidence indicates that increased UOG traffic in areas of intensive UOG development in the USA has resulted in increased incidence of accidents in affected communities.
6.2.4 Risk of accidental release of hazardous material during transportation
There is a risk that truck accidents could lead to chemical or wastewater spills. This could include fracturing fluid, chemical additives, flowback water, or produced water. There are systems in place in the UK to manage the impact of chemical spillage in the event of a traffic accident. These controls would reduce, but not fully eliminate, such risks.
6.2.5 Air pollution impacts
The increases in vehicle movements would result in an increase in emissions of air pollutants. The Roseacre Wood case study suggests that road traffic flows associated with an individual development are not likely to result in significant air quality impacts. However, the potential for localised impacts would depend on the nature, scale and location of a proposed development. The potential for localised impacts on air quality would need to be taken into account in the environmental assessment of any UOG development.
Noise associated with traffic movements to and from UOG facilities could potentially affect nearby residents. Noise impacts would be determined by factors such as vehicle type, load and speed, type of road surface, road grade, distance from the road to sensitive receptor, road gradient, ground condition, and atmospheric conditions. Any Environmental Impact Assessment for UOG operations should consider noise as with any other development where an increase in traffic is forecast to occur.
6.2.7 Nature conservation
UOG activities can potentially affect biodiversity via a number of routes. In relation to traffic, the impacts potentially relate to accidental spills, sediment run-off and possibly new road construction or increased traffic movements in sensitive areas. The likely setting of shale gas development in Scotland means that impacts on remote habitats are unlikely. However, there would be a risk of harm to habitats which may be valuable in their local setting. Any such effects would need to be considered during the planning and EIA process.
6.3 Mitigation measures
Mitigation of potential community impacts from road traffic associated with UOG development should take place via the strategic and land-use planning processes.
6.3.1 Strategic planning
The Scottish planning system is used to guide decisions about the future development and use of land and identifies the locations and conditions under which development should and should not happen. Scottish Planning Policy ( SPP) in 2014 which sets out the national planning policies which reflect Scottish Ministers' priorities for operation of the planning system and for the development and use of land. Transport forms a key role within SPP and is supported by Planning Advice Note ( PAN) 75, "Planning for Transport".
PAN 75 provides good practice guidance which planning authorities, developers and others should carry out in their policy development, proposal assessment and project delivery. As with any other traffic-generating development, UOG project developers should expect to carry out assessment and mitigation of traffic impacts in accordance with PAN 75.
Strategic Development Plans set out the vision for the long term development of Scotland's city regions and follow the overarching vision for Scotland identified in NPF 3 and SPP. Clydeplan and SESplan make reference to UOG development, and mandate the setting of appropriate policies in local development plans.
Local Development Plans provide the vision for how communities will grow and develop in the future. A local development plan could include specific policies relating to the transportation impacts of UOG development. For example, the Clackmannanshire Local Development Plan makes specific reference to transportation of water for hydraulic fracturing, and indicates that preference would be given to sites that could import water by pipeline.
As set out in Section 5.5, supplementary guidance for assessing the merits of UOG sites and ensuring the appropriate management of development could be developed. This could be in the form of a PAN or a planning circular, or could be developed as Supplementary Planning Guidance by individual authorities. This would assist planners and developers in narrowing and prioritising their areas of search for appropriate sites. Specific guidance would also assist in the preparation and evaluation of documents including Environmental Statements, Traffic Management Plans etc. Local communities could refer to this guidance to identify what level of assessment, management and mitigation of transportation impacts they can expect.
6.3.2 Land-use planning
Any planning application for UOG development which would generate significant traffic movements should be made subject to an Environmental Impact Assessment ( EIA), using the powers available to planning authorities if necessary. An EIA would include a requirement for assessment of impacts relating to traffic movements. The assessment must determine if the proposed development would have a significant detrimental impact, and identify if any mitigation measures are required. Any mitigation measures should be clearly defined in the Environmental Statement. These may include measures for mitigation of traffic impacts by design, following the principles set out in Section 5.5. One of the key design measures is likely to include avoidance of transportation of water to and from the site by road, where possible
The most appropriate means of implementing a range of mitigation measures is through a Traffic Management Plan ( TMP). This enables a flexible approach to be taken to managing traffic impacts. TMPs are often requested by local authorities at the planning consent stage by means of a prescriptive condition attached to the issued consent.
6.3.3 Recommendations for mitigation
To ensure that appropriate mitigation measures are identified, implemented, enforced and managed, the following is recommended.
1. National, regional and local plans should set policies to guide the development of UOG resources, in the event that the moratorium is lifted. The Strategic Environmental Assessment which informs the strategic planning process should include consideration of multiple UOG developments in a locality and outline how the potential cumulative impacts of such development should be managed. For example, SEA could consider potential for effects on regional air quality due to traffic associated with multiple sites, or potential cumulative impacts of traffic noise from multiple sites. SEA could also be used to assess and manage the potential effects of development of multiple sites on protected natural habitats and species.
2. All planning applications for UOG development should be made subject to an Environmental Impact Assessment as discussed above.
3. A "Framework Traffic Management Plan" should be required to support all planning applications for UOG sites. The purpose of the document would be to demonstrate how traffic impact would be minimised and would clearly state what measures would be put in place. A full TMP should then be prepared post-planning and should be subject of a planning condition. This should include arrangements for traffic monitoring.
4. Discussions should take place between the developer and the local authority at the planning application stage with regards to the provision of a Roads Condition Survey and provision of an appropriate financial bond to cover any required road repairs. If required, this should be subject of a planning condition.
5. At appropriate sites, the developer should be required to appoint an Enforcement Officer post planning agreement to ensure that mitigation measures are implemented and enforced throughout the life of the project. This requirement may be subject to minimum thresholds associated with the forecast traffic impact of the proposed development.
6. It is understood that UK Onshore Oil and Gas is working with the industry, the Road Haulage Association and Fleet Operator Recognition Scheme on a set of key principles in considering transportation for onshore oil and gas. When published, these can be evaluated by planning authorities and, if appropriate, taken into account in considering and determining planning applications for UOG development, and identifying appropriate mitigation.
6.4 Residual community impacts from transportation
Assuming that appropriate strategic development policies are put in place, and appropriate mitigation is carried out, some residual community impacts due to transportation can be expected to remain. Local communities would experience an increase in traffic numbers, potentially for an extended period of a number of years. This might be experienced as an increase in HGV movements on local roads, together with associated road improvements such as junction improvements or passing places.
Any increase in vehicle movements could result in an increase in noise, vehicle exhaust emissions, road damage, or traffic accident risks, which may be identified as negligible, or may require mitigation. Mitigation of such traffic impacts would require specific management and financial resources which would need to be secured through the planning process. Provided the planning and EIA system is properly implemented, any significant impacts would be avoided through the use of appropriate mitigation measures.