<p>The tragic events of September 11th, 2001 (9/11) have had a profound and unimaginable impact on activities in all of lower Manhattan, and the New York City metropolitan region. Profound, of course, because of the huge loss of life, and because of the continuing sense of trauma of the survivors. These events have also provided a monumental challenge to transportation and city planners because there are no guidelines in US planning/engineering literature on how to manage after such an event occurs.</p>