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Understanding Two-lane highway LOS concept

Sudheer Dhulipala
Ulteig Engineers
Understanding Two-lane highway LOS concept was posted on March 26th, 2015 at 5:12 PM EDT
regarding Chapter 15: Two-Lane Highways

I am trying to understand the concept of LOS for Class III two-lane Highways. It is mentioned in HCM 2010 Chapter 15 that the LOS for these facilities is based on percent of free flow speed. So, the LOS is determined by the ratio of average travel speed and free flow speed. What I am not able to understand is that the FFS is reduced if the facility has higher access density and narrower shoulders. Since the FFS is in the denominator of the ratio, this will lead to better LOS for higher access density and narrower shoulder roads all else being same. This makes comparing two facilities difficult. Can someone explain the reasoning behind this procedure?

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