Determine Analysis Flow Rate One of the fundamental inputs to a traffic analysis is the actual traffic volume on the roadway, in vehicles per hour, which is given the symbol V. Generally, the highest volume in a 24-hour period (the peak-hour volume) is used for V in traffic analysis computations. However, this hourly volume needs to be adjusted to reflect the temporal variation of traffic demand within the analysis hour and the impacts due to heavy vehicles. To account for these effects, the hourly volume is divided by adjustment factors to obtain an equivalent flow rate in terms of passenger cars per hour (pc/h). Additionally, the flow rate is expressed on a per- lane basis (pc/h/ln) by dividing by the number of lanes in the analysis segment.