The report 'Review of Impact of Well Site Infrastructure' (NB: Link to external PDF) of the M4ShaleGas project states that the exploitation of unconventional hydrocarbon resources will generate a variety of surface transport activities. These will occur at every stage of development: from initial exploration and test drilling, through production well development, through to final well-plugging and decommissioning. The primary, traffic-related, concern regarding hydraulic fracturing (colloquially 'fracking') activities is the possible use of large numbers of tankers and heavy trucks to transport the required volumes of water, sand and proppant materials. Likewise the removal of contaminated flowback liquids or produced water, may be problematic in the absence of adequate pipeline or recycling facilities, as these must then be tankered to water treatment facilities.

Surface transport activities have been identified as having an impact on the environment through:

• Greenhouse Gas (GHG) emissions (primarily CO₂);
• Emissions of gases that cause Local Air Quality (LAQ) issues (primarily NO_x/NO₂ and particulate matter);
• Creation of noise, and associated annoyance and disturbance;
• Damage to both road surfaces and road sub-structures, leading to cracking and 'pot-holeing';
• Congestion, disruption to other traffic, and community severance;
• Occurrence of incidents, accidents and spills;
• Light pollution.

Whilst ultimately adherence to regulations, best practice, sound prior planning, development of supporting infrastructure and improvements in technology may drastically reduce the need for, and impacts of, traffic activities, there remains the requirement to be able to assess the impact of operations in a holistic fashion – hence the development of the Unconventional Hydrocarbons Traffic Impacts Model (Version 2) - UHTIMv2.