Problem 5 Discussion |
ID# C1050D1 |
Problem 5:
Discussion
What have we learned? We have discovered that the two-lane rural
highway analysis method has some difficulty dealing with hamlets. It has
difficulty both determining the PTSF and the average travel speed. We know
for the hamlet that the PTSF should be 100%. We have over-ridden the
methodology’s estimate of 71.6% and entered 100% in the table. The
method also seems to underestimate the speed. An analysis based around the
TWSC unsignalized intersection analysis procedure leads us to conclude
that the average speed through the hamlet should be about 33.3 mph instead
of 24.3 as predicted by the two-lane rural road methodology. We have also
seen that if we explore an alternate solution strategy of building a
bypass there may be a tradeoff involved. The PTSF improves, as does the
average speed, but the total travel time across the highway segment is a
minute longer due to the extra travel distance involved. Keeping with
the original way that the problem was posed, Idaho Transportation
Department will have to
decide if the extra minute of travel time is a fair tradeoff for the
improved perception of highway performance.
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