Investigating the traffic-related environmental impacts of hydraulic-fracturing (fracking) operations.

Hydraulic fracturing (fracking) has been used extensively in the US and Canada since the 1950s and offers the potential for significant new sources of oil and gas supply. Numerous other countries around the world (including the UK, Germany, China, South Africa, Australia and Argentina) are now giving serious consideration to sanctioning the technique to provide additional security over the future supply of domestic energy. However, relatively high population densities in many countries and the potential negative environmental impacts that may be associated with fracking operations has stimulated controversy and significant public debate regarding if and where fracking should be permitted. Road traffic generated by fracking operations is one possible source of environmental impact whose significance has, until now, been largely neglected in the available literature. This paper therefore presents a scoping-level environmental assessment for individual and groups of fracking sites using a newly-created Traffic Impacts Model (TIM). The model produces estimates of the traffic-related impacts of fracking on greenhouse gas emissions, local air quality emissions, noise and road pavement wear, using a range of hypothetical fracking scenarios to quantify changes in impacts against baseline levels. Results suggest that the local impacts of a single well pad may be short duration but large magnitude. That is, whilst single digit percentile increases in emissions of CO2, NOx and PM are estimated for the period from start of construction to pad completion (potentially several months or years), excess emissions of NOx on individual days of peak activity can reach 30% over baseline. Likewise, excess noise emissions appear negligible (<1dBA) when normalised over the completion period, but may be considerable (+3.4dBA) in particular hours, especially in night-time periods. Larger, regional scale modelling of pad development scenarios over a multi-decade time horizon give modest CO2 emissions that vary between 2.5 and 160.4kT, dependent on the number of wells, and individual well fracking water and flowback waste requirements. The TIM model is designed to be adaptable to any geographic area where the required input data are available (such as fleet characteristics, road type and quality), and we suggest could be deployed as a tool to help reach more informed decisions regarding where and how fracking might take place taking into account the likely scale of traffic-related environmental impacts.

The influence of urban land-use on non-motorised transport casualties.

The relationship between non-motorised road traffic casualties and land-use was investigated in two zones of approximately 8 km2 in Newcastle upon Tyne, England. Road traffic accidents are, more usually, analysed in relation to traffic flow, on the assumption that the latter can be derived from land-use data. Here, a direct relationship between primary functional land-use and non-motorised casualties is estimated. We review past work in this area. A shortcoming of casualty data is that it does not record the origin and destination of the journeys being undertaken when the accident occurred. A method was established to identify zones within which most accidents could reasonably be expected to be related to the land-uses within that zone. Generalised linear models were developed using non-motorised casualties as the response variable, with primary functional land-use, population density and junction density as explanatory variables. Separate models were constructed for each combination of cyclists and pedestrians, adults and children, working and non-working hours in city centre and suburban analysis zones. In general, the study found that pedestrian casualties in the city centre zone are particularly associated with an increase in retail and community land-use during working hours. In the city centre zone, out of working hours, an increase in retail land-use (almost certainly clubs and bars) is also associated with an increase in pedestrian casualties. An increase in cyclist casualties during working hours (in the non-pedestrianised area) is associated with an increase in retail land-use.