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DIURNAL VARIATIONS IN TRAFFIC FLOW AND CARBON MONOXIDE CONCENTRATIONS
Citation:
DeMarrais, G. DIURNAL VARIATIONS IN TRAFFIC FLOW AND CARBON MONOXIDE CONCENTRATIONS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/4-77/016 (NTIS PB266743).
Description:
Traffic count and carbon monoxide (CO) data for January and July from three states are compared in order to reveal any diurnal variations in the two measurements. The diurnal patterns for the 18 traffic count stations indicate that there are average patterns of traffic flow that are representative of all stations for periods of one month. Comparisons of data for the 36 CO monitoring stations show correlations which vary from large positive to large negative. However, eliminating a few monitoring stations which show relatively poor correlations yields groups within each state that have consistent patterns. The diurnal variations in CO concentrations are not well correlated with traffic patterns. Part of the poor correlation appears to be due to the diurnal variations in vertical mixing and wind speeds and part to the exposures and locations of the sampling instruments.