How does ME-Design choose which climate file start date to use?
ME-Design uses hourly climate data files (HCD) as input into the pavement design algorithm. As a user I can enter an arbitrary number of years of climate data. If I enter say 30 years of climate data and then set an analysis period of 20 years, what data does the program use? Does it use the first value in the list or the last 20 years of the file? What if my analysis period is greater than the amount of climate data entered?
ME-Design checks to see if the pavement construction date is within the entered climatic data range. If it is, the analysis uses that date.
If the pavement construction date is not included in the entered climate data range, the analysis always uses the earliest month/day in the list that matches the pavement construction date. It does this so that the answer is the same at years 1,2,5,10 whether an analysis is run for 10, 20 or 30 years.
If the analysis period is longer than the available climate data, the data is reused starting from the earliest applicable date.