A review has been implemented on the state of the practice and research needs have been identified on methods for forecasting bicycle and pedestrian travel. The focus is on methods that forecast how many people will use a new bicycle or pedestrian facility or how many additional people will walk or bicycle in response to facility or network improvements. Overall, there appears to be a shortage of methods that practitioners with limited technical resources can use but are nonetheless accurate enough for planning purposes. In addition, existing research on the factors influencing the decision to walk or bicycle often has not been translated into usable forecasting methods. Three major recommendations are made. First, in the short term, a sketch-planning manual for bicycle and pedestrian forecasting is needed to give planners access to the basic data, tools, and methods required to estimate future demand. Second, further research is needed into specific factors influencing bicycle and pedestrian travel behavior, with an emphasis on identifying key factors that can be included in forecasting models. Third, bicycle and pedestrian considerations should be integrated into mainstream transportation models that traditionally have focused on vehicle travel. Inclusion of nonmotorized modes in travel models will improve capabilities for forecasting both motorized and nonmotorized travel and will help place bicycles and pedestrians on a "level playing field" with motorized modes in transportation planning.

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There has been considerable renewal of interest over the seriousness and nature of the air quality problems in this country. The need for transportation and other forms of mobile source controls is dependent on the magnitude of the current problem and the rate at which air quality is improving. Trends in monitored ozone levels for 20 serious and severe nonattainment areas over the 14-year period, 1980–1993, are examined. Trends are examined using ambient air quality data contained in the Aerometric Information Retrieval System data base maintained by the Environmental Protection Agency (EPA). Trends in two measures are analyzed: the maximum hourly ozone value for the second highest violation day and the number of violation days per year. Tests of the statistical significance of air quality trends were conducted, including consideration of the effects of geographic scale, meteorological variables, and economic growth. The results show that, on a nationwide basis, there is a significant downward trend in ozone levels. However, not all the year-to-year variations can be explained by a simple trend, and there also are other factors that have an important influence on peak ozone concentrations. The analyses showed statistically significant results in different urban areas and geographic regions; it also showed that omitting meteorological variables results in an overestimation of the downward trend for the particular urban areas and time period analyzed.