The AM and PM peak hours are not always inversely related. Peak hour percentages in terms of the percentage of total daily traffic that is occurring in the AM/PM peak hour are determined separately for both the peak hours. The percentages are intended to be a representation of the existing traffic patterns. Typically, traffic counts are collected in the form of TMCs and segment counts. Assuming traffic counts are taken on a typical weekday with no major events or disruptions, they represent peak hour percentages for the AM and PM K-factors. The peak hour percentages are then applied to the ADTs to develop projected AM and PM peak hour volumes. It is recommended that the traffic counts collected be validated against STARS data, previous counts, or traffic forecasts.

Turning movement traffic projections are estimated by applying existing TMC percentages at each approach to the ADT volumes. TMCs are typically rounded to 50- vehicle increments. This avoids an overestimation of traffic on side streets. The traffic projections are then balanced along the corridor.

For an

example

on calculating AM and PM peak hour traffic projections, see

Appendix D, Section 3 – Peak Hour Projection Calculations

.