Methods: Noise measurements were conducted in downtown areas in three cities in the UnitedStates:
Atlanta, Losangeles,andNewYorkCity.Foreachcity,wemeasuredambientnoiselevels,andassessed
their correlationwithsimultaneouslymeasuredvehiclecounts,andwithtraffic dataprovidedbylocal
Metropolitan PlanningOrganizations(MPO).