Since the average daily traffic represents the most common traffic demand information for highway networks, the COMSIS approach is well suited for project planning analysis. This method provides an overall measure of the effect of volume changes and capacity improvements on travel time without requiring detailed profiles of volumes by time of day. To use the speed look-up tables, prior determination of the average weekday traffic (AWDT) and roadway capacity is needed. Average weekday traffic (AWDT) can be determined by applying a conversion factor to the AADT. After AWDT and capacity are determined, the hourly speed, daily speed, peak speed, and off-peak speed can be estimated from speed look-up tables such as Table 5.1