Sub-problem 2b - Page 3 of 3 |
ID# C102B03 |
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.
Exhibit
1-23. U.S.95/Styner-Lauder
Signalized Intersection Analysis with Varied Arrival Types (Datasets) |
Arrival Type |
EB |
WB |
NB |
SB |
LT |
TH/RT |
LT |
TH/RT |
LT |
TH/RT |
LT |
TH/RT |
2 |
19.1 |
20.7 |
18.9 |
22.9 |
5.7 |
6.1 |
7.9 |
8.8 |
3 |
19.1 |
20.7 |
18.9 |
22.9 |
5.7 |
6.1 |
5.9 |
6.6 |
4 |
19.1 |
20.7 |
18.9 |
22.9 |
5.7 |
6.1 |
3.8 |
4.2 |
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.
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