National Institute for Transportation and Communities

Bicycling in the United States is disproportionately unsafe as a transportation mode. Despite comprising a smaller share roadway users, bicyclists are twelve times more likely to be killed in a traffic crash with a car than car occupants (Pucher and Dijkstra, 2003). Bicyclists involved in a collision with a car are three times as likely to suffer a serious injury (Rivara et al., 1997) and significantly more likely to suffer a traumatic brain injury (Juhra et al., 2012) than bicyclists in non-... Read More

This research seeks to understand the characteristics of transitions as freeway traffic changes from one state to another. This study addresses the features of two types of transitions; transitions near a merge and transitions along shock waves during the onsets and dissipations of queues at several freeway sites. Individual vehicle trajectory data were analyzed for studying the transitions near a merge. The length of a transition zone was measured by analyzing the spatial changes in flow, de... Read More