Sub-problem 6d: Planning Analysis at SH-8 Intersection

The twenty-year projected volumes for this intersection, adjusted for the peak period factor are shown in Exhibit 1-54.

This is an unusual intersection that will require careful thought before applying the quick estimation method. Look again at Exhibit 1-4. The departure roadway to the north is one-way away from the intersection, and the west leg of the intersection is one-way eastbound. Therefore, there is no westbound through movement, no northbound left turn, and no southbound traffic at all. 

So, the first thing to consider is the type of treatment (permitted, protected, protected plus permitted or not opposed) to specify for each of the left turns. Exhibit 1-55 shows the signal phasing that is currently being used. The eastbound and westbound movements are fully separated, and so the "Not Opposed" treatment will apply. While the northbound and southbound left turns do not exist, they must be specified as permitted because of the way that the quick estimation method represents traffic movements. For more detail on this subject, see the discussion presented under sub-problem 6c.