Sub-problem 2b: Analysis of the Signalized Intersection Considering the Effects of Adjacent Intersections

Step 2. Results

The effect of the arrival pattern of vehicles from the Sweet Avenue intersection to the Styner-Lauder Avenue intersection depends on when platoons from Sweet Avenue arrive at Styner/Lauder. The HCM classifies the way in which platoons arrive at a signalized intersection according to arrival type. Exhibit 1-23 shows the results of the delay calculations for this problem, assuming three arrival types (2, 3, and 4). Again, for this problem, we've found from field studies that arrival type 4 best describes the conditions likely to be present once the intersection is signalized.

It should be evident even before we do any analysis that varying the arrival type from Sweet Avenue will have no effect on the eastbound approach, the westbound approach, or the northbound approach, since none of these approaches are affected by the Sweet Avenue signal.

However, we do see some effect for the southbound approach. For the case in which we don't consider the Sweet Avenue signal (see Exhibit 1-11), the average control delay is computed to be 6.6 seconds per vehicle for the through and right turning traffic. This is shown as arrival type 3 in the table. For our projected condition, with favorable progression and arrival type 4, the delay is reduced to about 4 seconds per vehicle for this movement. While this is not a significant decrease, it does represent some effect for traffic on this approach. For purposes of comparison, we have also shown a less favorable progression condition, arrival type 2. Here, the average control delay increases to nearly 9 seconds per vehicle for the through and right turning traffic.