  Disruptions to transportation networks are inevitable. Currently, most
mandated development-related transportation planning is intended to prepare for
frequently occurring and observable disruptions while low probability events
that have not yet materialized attract less attention. When road networks are
not resilient, these unpredictable events can cause significant delays that may
not be proportional to the extent of the disruption. Enhancing resilience can
help in mitigating consequences of disruptions but requires financial
investment that is difficult to justify given that low probability event may
not have materialized. This paper highlights economic implications of
unmitigated random disruptions in urban road systems and makes the case for
investment in transportation network resilience. We utilized a model of urban
transportation network performance that quantifies resilience and demonstrated
its integration with microeconomic transportation planning model REMI
TranSight. The model was applied to 10 cities in the USA to calculate several
economic indicators under baseline scenario where economic impact was assumed
to be proportional to the magnitude of disruptive events and under a test
scenario where the magnitude of disruption was used to calculate additional
delays in transportation networks and these additional delays were explicitly
integrated in REMI model. Results show that GDP losses suffered as a result of
disruption may be far more significant in the case scenario and economic output
is not necessarily back to normal in the year the following disruptive event.
We thus conclude that support for investment decisions on network efficiency
and resilience management should be based on a framework that utilizes
resilience, quantified in terms that are compatible with standard practice, and
scenarios to test the implications of topological attributes.
