Highway Safety Impacts Related to Marcellus Shale Drilling Activity in Bradford County, Pennsylvania

Open Access
Crisafi, Jonathan Charles
Graduate Program:
Civil Engineering
Master of Science
Document Type:
Master Thesis
Date of Defense:
June 29, 2015
Committee Members:
  • Eric Todd Donnell, Thesis Advisor
  • Marcellus
  • transportation
  • safety
  • trucks
In the mid- to late-2000s, drilling to exploit the Marcellus Shale natural gas play began to accelerate in the northwestern United States, specifically Pennsylvania. The sudden surge in heavy vehicle traffic, needed to support natural gas drilling operations, on aging, rural, and previously lightly trafficked roadways in Pennsylvania has had a variety of negative impacts, many of which have not been quantified, raising many questions about the benefits and costs associated with this activity. In terms of traffic safety, the question presents itself as how does the notable change in traffic composition due to Marcellus Shale drilling activity affect crash frequency? This paper investigates crash frequency in Bradford County, Pennsylvania where drilling activity began in 2007 and increased through 2010. Preliminary analysis shows increased total crashes and heavy vehicle-related crashes after 2007, compared to previous years. Using negative binomial and random effects negative binomial statistical models to investigate further, annual crash frequency per municipality was used to model total crash frequency and heavy vehicle-related crash frequency. On a municipality by municipality basis, a variable (referred to as “well frequency”; i.e. wells per municipality) was used to estimate the amount of drilling activity for a particular area. The negative binomial models were found to fit the observed data better when compared to the random effects negative binomial model, which was initially considered to try to capture variability between municipalities that was not captured otherwise. Modeling results suggests that Bradford County experienced an increase in total crashes and heavy vehicle crashes in the post-Marcellus period compared to the pre-Marcellus period and the presence of increasing well frequency.