摘要：Portland city planners have routinely planned for an increase in bicycle commutership and a decrease in automobile commutership. This paper discusses the latest data on Portland car and bicycle use. Portland and Multnomah County are observing an increase in single occupancy vehicle commuters, car ownership, and gasoline consumption. Bicycle use in Portland is found to have followed a logistic curve pattern since the early 1990s. The authors present an ordinary least squares model to explain bicycle ridership on the Hawthorne Bridge and the recently constructed Tilikum Crossing. When controlling for other factors such as weather and daylight, the Tilikum Crossing has added an average of 1,137 bicycle rides per day to total east-west rides across the Willamette River, some of which are diverted from the Hawthorne Bridge.
关键词：ordinary least squares; regression; transportation economics; Portland; bicycle infrastructure; commuting
