Persistence Factors For Carbon Monoxide Modeling Near Intersections


Hourly meteorological data covering ten years for four cities in Florida were obtained from the National Climatic Data Center. Typical 8-hour turning movements (TM's) were obtained from FDOT for several major intersections in Florida. A computerized procedure was written to average and extend these 8-hour TM's to one 18-hour TM scenario for a hypothetical major intersection, using factors from the Quick Response manual. The TEXIN2 model was used to obtain hourly CO concentrations for each day of the year, which were combined to derive total persistence factors (TPF's). The TPF's for 10 years for one city in Florida were analyzed using several approaches to help choose a reasonable worst-case TPF. The daily TPF's exhibited a wide distribution and the highest TPF's were inversely correlated with the 1-hour CO concentrations. The TPF's associated with the highest eight percent of all the 1-hour CO concentrations averaged about 0.42, and ranged from less than 0.2 to over 0.7. A recommended worst-case value of the TPF for use in Orlando, Florida is between 0.50 and 0.54, based on several different ways of analyzing the data.

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Publication Title

Proceedings - A&WMA Annual Meeting



Document Type

Article; Proceedings Paper

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Socpus ID

0024920679 (Scopus)

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