1.1 Study context
On 28 January 2015, the Scottish Government announced a moratorium on environmental and planning consents for the development of all unconventional oil and gas ( UOG) extraction in Scotland, including, but not exclusively, that using hydraulic fracturing. This was extended to cover underground coal gasification ( UCG) on 8 October 2015. The aim of this moratorium was to enable the Scottish Government to take a cautious, considered and evidence-based approach to the development of unconventional oil and gas in Scotland. The imposition of a temporary, open-ended moratorium gives the Scottish Government the opportunity to take a number of key steps to developing a robust policy in relation to UOG:
- Undertake a full public consultation on unconventional oil and gas extraction
- Commission a full public health impact assessment
- Conduct further work into strengthening planning guidance
- Look at further tightening of environmental regulation.
To support this programme, the Scottish Government has announced five studies to provide the required scientific and technical evidence on UOG development. These studies cover the following topics:
- Understanding and Mitigating Community Level Impacts from Transportation (this study)
- Decommissioning, Site Restoration and Aftercare - Obligations and Treatment of Financial Liabilities
- Understanding and Monitoring Induced Seismic Activity
- Economic Impacts and Scenario Development
- Climate Change Impacts
When announcing the moratorium, Fergus Ewing (Scottish Government Energy Minister) said, " We recognise that local communities are likely to bear the brunt of any unconventional oil and gas developments, particularly in terms of increased traffic and related emissions and noise impacts. These are issues that must be researched further." This project is the cornerstone of Scottish Government's work programme to deal with these important issues for local communities.
1.2 Project objectives
The traffic impacts of development are among the most evident for communities where widespread development of UOG resources takes place. The focus of this project was on characterising the traffic movements associated with UOG development (both in terms of volumes and vehicle types), identifying the associated environmental impacts (including emissions and noise impacts highlighted by the Minister), and outlining the regulatory and planning means by which these impacts would be dealt with, in the event of UOG development going ahead in Scotland. Underground coal gasification is not within the scope of this project.
The overall objective of this project is to better understand the potential for increases in traffic volumes in the vicinity of UOG activity during the exploration, appraisal, production, and decommissioning & restoration stages. Building on this, Scottish Government wishes to understand the link between transport impacts and the magnitude of operations, their duration, and the types of locations affected by traffic movements. This is not a straightforward issue with linear correlations between the scale and duration of operations and traffic numbers, because UOG exploration and development would typically take place at multi-well pads, and traffic movements would be strongly affected by the details of development. Traffic impacts would also be affected by the site context ( e.g. proximity of sensitive locations to roads carrying additional traffic).
The Scottish Government also wishes to develop an improved understanding of the reasons for traffic movements linked to UOG development. This will enable appropriate assessments to be carried out, and in particular it will enable guidance on reducing traffic movements to a minimum, and managing unavoidable traffic impacts to be developed, should the moratorium on UOG development be lifted. This will enable a view to be taken on the minimum likely traffic impact of UOG development scenarios, in order to assist with policy decisions in relation to the future of UOG development in Scotland.
Looking at individual sites and potential transportation-related impacts, the Scottish Government wishes to understand the magnitude of traffic flows, the likely variation in traffic flows and impacts at different locations. In the USA, where UOG development is most advanced, shale gas and similar installations have been developed in a very wide range of locations, from remote rural sites through sites located in industrial areas, sites close to residential areas, and sites in urban centres.
Hence, in summary, the project aims are:
- To improve understanding of the scope and scale of increased traffic volumes in communities around sites, over the four stages of unconventional oil and gas development (exploration, appraisal, production and decommissioning & restoration).
- To improve understanding of the range of potential impacts, and duration of impacts, of these traffic volumes, and characterise potential impacts in sites of different types.
- To identify robust regulatory and other options that could mitigate impacts on communities and the environment.
1.3 Onshore oil and gas in Scotland
Shale oil and gas reserves in Scotland are located principally across the central belt (see Figures 1 and 2). In relation to Coal Bed Methane, five site investigations had been initiated to 2014, located in historic coal mining areas in Falkirk, Dumfries & Galloway, East Fife, Lanarkshire and West Fife. Consequently, if UOG development proceeds, installations could potentially be located in a wide range of areas, including densely populated urban areas, suburban areas, remote rural areas, coastal locations and sensitive habitat zones (subject to other considerations such as the current ban on activities involving hydraulic fracturing in protected areas of the UK).
Figure 1: Area prospective for shale oil in Scotland 
Figure 2: Area prospective for shale gas in Scotland 
UOG development in both urban and rural areas could potentially result in traffic using unsuitable roads, and it is important for Scottish Government to understand the risk of this occurring, the mitigation measures available, and the potential environmental and community implications.
The development of an individual UOG well is characterised by an intensive phase of activity during the site preparation, well drilling, hydraulic fracturing and completion stages, with associated traffic movements. After the well is completed, it can be expected to operate with much lower levels of activity for a period of around 5 to 10 years. During this time, the hydrocarbon production rate typically drops from an early peak, until it reaches a point when the operator may opt to refracture the well. This would then result in a further phase of intensive activity and associated traffic movements. Refracturing has become less common in recent years, with recent data indicating that approximately 1% of existing wells in the US are refractured each year based on a survey of 91,000 wells.  In the US, it is estimated that refracturing will account for up to 11% of horizontal well fracturing activity by 2020. 
This pattern of activity may be representative for drilling of small numbers of wells during the exploration phase. However, a different pattern is likely to emerge in the event of more widespread development of a shale gas field, as discussed in our analyses for the European Commission  and CCAN.  The use of well pads with 10 - 20 wells would result in the initial phases of well development taking place over a longer period than would be the case for smaller well pads. Additionally, the relatively thin and fractured shale formations in Scotland  compared to those in England may result in less intensive development at an individual well pad than could be expected to occur in England.  These features of gas field development have been explored in the economic impact assessment, and the implications for transportation explored here. However, the transportation impacts for communities living close to any individual site would depend on the phasing of activities at that site.
1.4 Structure of this report
The study methodology is set out in Section 2 of this report. The relevant regulatory and planning framework for Scotland is presented in Section 3. Section 4 provides data on material requirements and estimated traffic movements associated with UOG development in Scotland. Section 5 provides a discussion of potential impacts of road traffic associated with UOG development, and outlines how these impacts could be managed if UOG development is permitted to proceed. The study conclusions and recommendations are set out in Section 6.
1.5 Stakeholder engagement
The following organisations were consulted during the course of this project, and provided valuable feedback:
- Broad Alliance - "a coalition of Scottish communities opposed to onshore and near-shore unconventional oil and gas development"
- Scottish Environment Link - "the forum for Scotland's voluntary environment organisations, with over 35 member bodies representing a range of environmental interests with the common goal of contributing to a more environmentally sustainable society"
- UK Onshore Oil and Gas - "the representative body for the UK onshore oil and gas industry including exploration and production"