Recent working paper

• Cui, Mengying and Levinson, D. (2015) Accessibility Analysis of Risk Severity  (working paper)

Risk severity in transportation network analysis is defined as the effects of a  link or network failure on the whole system. Change accessibility (reduction in the number of jobs which can be reached) is used as an integrated indicator to reflect the severity of a link outage.  The changes of accessibility before-and-after the removing of a freeway segment from the network represent its risk severity. The  analysis in the Minneapolis – St. Paul (Twin Cities) region  show that links near  downtown Minneapolis have relative higher risk severity than those in  rural area. The geographical distribution of links with the highest risk severity displays the property that these links tend to be near or at the intersection of freeways. Risk severity of these links based on the accessibility to jobs and to workers at different time thresholds and during different dayparts are also analyzed in the paper. The research finds that network structure measures: betweenness, straightness and closeness, help explain the severity of loss due to network outage.

Keywords: GPS data, congestion, network structure, accessibility