University of California Transportation Center

Commuting patterns between home and work were studied among 30,000 employees of Kaiser Permanente, a major health care provider in Southern California. The study tracked the differences between home and work location among employees over six years by analyzing employee records and responses to a survey of over 1,500 of the works. It was found that work trip lengths had in general not grown over the six year period. Growth of the work force had contributed more to the growth in local traffic congestion than had a lengthening of the work trip over time. The automobile remains the dominant mode of travel between home and work for these employees, and choices of residential location were found to be based upon many factors in addition to the home-work separation, such as quality of neighborhood and schools and perceived safety.