deletions | additions       diff --git a/Introcution.tex b/Introcution.tex  index 8e8c238..abdaf5a 100644  --- a/Introcution.tex  +++ b/Introcution.tex 
...
\section{Introduction}  Roundabouts are relatively new designs for intersection traffic management in North America. With considerable promises from abroad  in terms of safety, as well as capacity from abroad, capacity,  roundabouts are a staple of European road design and many studies have demonstrated reductions in accident probability and accident severity, particularly in Denmark \cite{Jensen_2013}, Sweden, TODO. design.  However, questions still remain regarding the feasibility of introducing the roundabout to regions were driving culture and road design philosophy differs and where drivers are not habituated to their use. This road user aspect is crucial for their implementation: roundabouts must manage traffic conflicts passively, for road user interactions are handled entirely by the road users by way of yielding behaviour and driving etiquette. This is in contrast with typical intersections managed by traffic-light controllers or even police traffic controllers. And while roundabouts share much in common with 4 and 2-way stops, they are still frequently used for high-capacity, even high-speed intersections which would not normally use 4 and 2-way stops. Resistance to adoption in some areas is still important, particularly from vulnerable users. users \cite{Hyd_n_2000, Stone_2002, Gran__2011, Perdomo_2014}.  While a number of European  studies cite reductions in accidents rates, accident probability and accident severity, particularly for Denmark \cite{Jensen_2013}, Sweden \cite{Bergh_1997, Hyd_n_2000},  few offer microscopic insight over the inner mechanics of driving behaviour that surrogate safety analysis provides which might be key to regional adaption of the roundabout design or implementation efforts. The objectives of this paper are to explore the impact of North American roundabout characteristics, their geometry and built environment, on driver behaviour and safety through microscopic, video-based trajectory data analysis. This represents one of the largest applications of surrogate safety analysis to date.