Sub-problem 6b: Consideration of a Grade-Separated Flyover
Step 1. Setup
It was demonstrated in Problem 5 that signalization would provide adequate capacity for the projected traffic volumes at this intersection, but v/c ratios would approach 90% and delays would be well into the LOS E range, especially for the minor movements. Further improvements are likely to require the elimination of conflicting movements by means of grade separation.
The HCM considers competing movements that are grade separated to be conflict free. Therefore an HCM analysis of the benefits of a grade separation will usually involve the elimination of movements from the intersection.
Consider:
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What additional data should be gathered to determine whether grade separation is appropriate?
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What conflicting movements might benefit from grade separation?
Discussion:
Take
a few minutes to consider these questions. Click continue when you are ready
to proceed.