What are ADT, AADT, and peak hour volume?

ADT (Average Daily Traffic) is the total traffic volume during a given period divided by the number of days. AADT (Annual Average Daily Traffic) is the total yearly traffic divided by 365, representing typical daily traffic. Peak hour volume is the highest hourly volume during a day, typically 8-12% of ADT. Design Hour Volume (DHV) is usually the 30th highest hourly volume of the year. These measures help size facilities and evaluate traffic conditions.