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Sub-problem 1b - Page 2 of 7

ID# C401B02

Sub-problem 1b: Analysis of the Eastbound Freeway Section

The eastbound section has two lanes and is divided into three segments:

bullet a one-mile segment with a 1-2% upgrade to the vicinity of Miller Road
bullet a one-mile segment with a 1-2% downgrade, and
bullet a final one-mile segment with a 5-7% downgrade ending at the I-787 interchange.

The first task is to specify the conditions. One important question is: where should we do the analysis? Should we use the 5-7% downgrade, the 1-2% upgrade, or the 1-2% downgrade? The HCM says: use the section that will produce the most conservative estimate of the LOS. That is, worst case governs.

So we’ll use the 1-2% upgrade section. In addition, because it is a mile long or more, we’ll assume it’s a constant grade, not a rolling or mountainous section. (As an aside, those categories don’t really have to do with where the facility is. They relate a lot more to the vertical profile of the segment. For example, a freeway running along a mountaintop is level even though it’s in a mountainous region.)

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