peak hour factor
peak hour factor
(OP)
whil looking at the formula for calculating peak hour factor, it seems as though the answer is the same as the highest 15 minute period time 4. if this is correct, why go through the bother of the calcs? if i am misinformed, what am i doing wrong?





RE: peak hour factor
phf = highest hour
highest 15 min x 4
It's a measure of how "peaky" the highest hour is. If the phf is high, than traffic is steady for the whole hour. If it is low, than most of the peak is in the peak 15 minutes.
RE: peak hour factor
RE: peak hour factor
RE: peak hour factor
HTH
RE: peak hour factor
RE: peak hour factor
Basically the data is in 15 minute chunks, and we analyse for 1 1/2 hours we then multiply as follows
00:00 fLOW IS 0
00:15 INTERPOLATED BETWEEN 00:00 AND 00:30
00:30 0.75 HOURLY FLOW
00:45 1.125 HOURLY FLOW
01:00 0.75 hourly flow
01:15 INTERPOLATE
00:30 0
This approximates to a normal distribution. Most of the software actually has this built in.
However for manual calcs we need to multiply all flows by 1.125 to account for localised variations within the 15 minute periods.