Carbon Monoxide from Traffic in Riyadh

Abstract

Concentrations of carbon monoxide (CO) were measured over a two‐year time period (1985‐1986) at three heavily‐traveled arterials in Riyadh. Measurements were made continuously including rush hours at three locations on each study arterial: one at the traffic centerline; and the other two at two sidewalk limits. In addition, the daily distribution of traffic volume and mix were measured and data on meteorological characteristics were obtained for each study arterial. During the rush hours, CO concentrations frequently exceeded 100 ppm. Both the mean 1‐hour and 8‐hour levels exceeded the Saudi Arabian Air Quality Standards (SAAQS) by a substantial margin. CO concentrations increased slightly over the two‐year monitoring period. This increase was statistically significant (α=0.05level) at nearly 50% of the measurement locations. Analysis of correlations revealed that factors of hourly traffic volume, wind speed, and the street aspect ratio demonstrated a high degree of linear association with the distributio...