All automatic count stations have been counted with FHWA 13-class vehicle classification and
grouped into the cordon count categories. Under this classification scheme, based on vehicle length,
the light truck category is overestimated compared to manual count stations because personal trucks
cannot be separated out from commercial trucks. Buses are also overestimated compared to manual count
stations because they cannot be totally separated out from some larger medium trucks or smaller heavy
trucks.
Database has been modified to reflect traffic volume in 15-minute ending times.
The Cordon Count is a one-day snap shot of traffic at each station counted by direction over
the period from 5:30 am to 7:30 pm. There are natural fluctuations in traffic volume and composition
by day of week, month, weather, geographic distribution of industrial and commercial activities in the
region and economic cycles. In these sense it should be noted that: