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Freeway Facilities Over-saturated Module Clarifications

Soheil Sajjadi
Freeway Facilities Over-saturated Module Clarifications was posted on March 7th, 2019 at 5:05 PM EST
regarding Chapter 25: Freeway Facilities: Supplemental

Comparison between HCM 6th Edition and the HCM 2000:

Q1: MO3 Calculation (Equation 25-15) in the last line, there is OFRF(i,t,p) in the 6th edition wherein HCM 2000 (Equation A22-12): its “ONRF (i,t,p). My question is that which one is correct? Is there any documentation on why it has changed?

Q2: The 6th edition in the 4th and 7th lines of the equation 25-18 use MF() where in HCM 2000 (Equation A22-15) its MO2. Which one is correct? Also, in the text of HCM 6th edition on line 4 and 5, MO2 has been mentioned but has not been used in ONRO (i,t,p) calculation. The dimensions of the variables have also changed from two to three. The variables such as RM(), ONRC(), and SC() seems to be a two-dimensional array (?). Why are we reporting it as two-dimensional arrays?

Q3: In HCM 6th edition ONRQ is calculated using Equation 25-21 wherein HCM 2000 calculated as in Equation (A22-18). However, the HCM2000 has ONRQ (I,t-1,p) expression as extra.

Q4: Where can we find the onramp queue calculation equation of (A22-31) of HCM2000 in the HCM 6th edition? Is there a difference in onramp queue calculation between the two methods?

(Edited July 7th, 2020 at 1:31 PM EDT)

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