The traffic volumes shown on the following maps are annual average daily traffic, or AADT, developed from 24-hour counts taken during 1999. These counts are factored to estimates of AADT taking into consideration volume variations among seasons of the year and days of the week. The difference in seasonal variation is the effect of trip purpose. Commuter and business-oriented travel occurs in more uniform patterns than recreational traffic which is subject to greater trip purpose variation.
Monthly variations are more severe on rural routes than on urban ones.
Rural routes serving primarily recreational traffic will have more severe variations than rural routes serving primarily business routes. Traffic variations by day of the week are also related to the area being served. Highways serving predominantly business travel show lower weekend volumes than weekday volumes. In comparison, peak traffic occurs on weekends on main rural and recreational access facilities. The magnitude of daily variation is highest for rural routes and least for urban routes.