Browsing by Subject "Travel time budgets"

Now showing 1 - 4 of 4
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    Activity, Travel, and the Allocation of Time
    (American Planning Association, 1995) Levinson, David M
    This paper analyzes 1968 and 1987-88 metropolitan Washington, DC household travel surveys to understand the daily allocation of time among different activities of individuals classified by work status and gender. The increase in female labor force participation rates has produced an increase in overall time spent at work per person. The increase in work trips and the simultaneous increase in nonwork trips has resulted in less time spent at home. People are substituting money for time spent at home, buying household services outside the home. The group of individuals who work at home is analyzed separately to obtain an understanding of this growing segment.
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    Density and the Journey to Work
    (Center for Business and Economic Research, University of Kentucky. Published by Blackwell Publishers, 1997) Levinson, David M; Kumar, Ajay
    This paper evaluates the influence of residential density on commuting behavior across U.S. cities while controlling for available opportunities, the technology of transportation infrastructure, and individual socio-economic and demographic characteristics. The measures of metropolitan and local density are addressed separately. We suggest that metropolitan residential density serves principally as a surrogate for city size. We argue that markets react to high interaction costs found in large cities by raising density rather than density being a cause of those high costs. Local residential density measures relative location (accessibility) within the metropolitan region as well as indexing the level of congestion. We conduct regressions to predict commuting time, speed, and distance by mode of travel on a cross-section of individuals nationally and city by city. The results indicate that residential density in the area around the tripmaker's home is an important factor: the higher the density the lower the speed and the shorter the distance. However, density's effect on travel time is ambiguous, speed and distance are off-setting effects on time. The paper suggests a threshold density at which the decrease in distance is overtaken by the congestion effects, resulting in a residential density between 7,500 and 10,000 persons per square mile (neither the highest nor lowest) with the shortest duration auto commutes.
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    The Rational Locator: Why Travel Times Have Remained Stable
    (American Planning Association, 1994) Levinson, David M; Kumar, Ajay
    This paper evaluates household travel surveys for the Washington metropolitan region conducted in 1968 and 1988, and shows that commuting times remain stable or decline over the twenty year period despite an increase in average travel distance, after controlling for trip purpose and mode of travel. The average automobile work-to-home time of 32.5 minutes in both 1968 and 1988 is, moreover, very consistent with a 1957 survey showing an average time of 33.5 minutes in metropolitan Washington. Average trip speeds increased by more than 20 percent, countering the effect of increased travel distance. This change was observed during a period of rapid suburban growth in the region. With the changing distributional composition of trip origins and destinations, overall travel times have remained relatively constant. The hypothesis that jobs and housing mutually co-locate to optimize travel times is lent further support by these data.
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    Temporal Variations on the Allocation of Time
    (Transportation Research Board, 1995) Levinson, David M; Kumar, Ajay
    This study investigates the allocation of time and trip-making across time-of-day, day-of-week, and month-of-year, as well as over the past forty years. Some interesting findings result. People are working much more, shopping somewhat more on weekends, and stay at home less today than forty years ago. Time spent in travel on each weekend day (Saturday or Sunday) exceeds that on any weekday, as it did forty years ago. Time spent shopping on a typical day in the busiest month (December) is more than double that in the least busy month (September). Monthly variations in daily time in travel exceed 10 percent. The time of day patterns of shop and other trips for workers and nonworkers are both rational: nonworkers peak in mid-day away from rush hour while workers peak just after work, indicating trip chaining.