The observation that increasing dispersion of employment opportunities leads to decreased travel times is reflective of a short-rem/phenomenon. Census-reported journey-to-work travel time is examined for the greater Philadelphia region, showing that more people are commuting by automobile, a mode usually associated with shorter journey times, but are reporting longer trip times. The finding is counterintuitive as it coincides with a period when new jobs were established in outlying areas and the region experienced a net loss in jobs. The study concludes that as job opportunities disperse into lower density areas, Philadelphia's existing high-capacity systems are underutilized, and transportation systems throughout the region that were designed for relatively low demand are becoming overwhelmed in time. The net effect is a breakdown of both the urban mass transit systems and the suburban and rural highway networks, the latter because of overuse and the former because of underuse.
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