  The use of naturalistic driving studies (NDSs) for driver behavior research
has skyrocketed over the past two decades. Intersections are a key target for
traffic safety, with up to 25-percent of fatalities and 50-percent injuries
from traffic crashes in the United States occurring at intersections. NDSs are
increasingly being used to assess driver behavior at intersections and devise
strategies to improve intersection safety. A common challenge in NDS
intersection research is the need for to combine spatial locations of
driver-visited intersections with concurrent video clips of driver trajectories
at intersections to extract analysis variables. The intersection identification
and driver trajectory video clip extraction process are generally complex and
repetitive. We developed a novel R package called ndsintxn to streamline this
process and automate best practices to minimize computational time, cost, and
manual labor. This paper provides details on the methods and illustrative
examples used in the ndsintxn R package.
