|
Sub-problem 5b - Page 5 of 5 |
ID# C105B05 |
Sub-problem 5b: Future
Analysis of 10-Mile
Segment of U.S. 95 With
Direct Recognition of the Hamlet
What volumes should
be used in the future conditions analysis?
Since the future conditions do not yet exist in the hamlet, we must project
or forecast the expected traffic conditions, estimate the resulting intersecting volumes, and do
the capacity analysis as outlined previously.
Exhibit 1-44
shows the intersecting volumes that have been projected. For this analysis,
the volumes into and out of each cross street were estimated on the basis of
the types and densities of land uses that each cross street is expected to
serve.
What additional assumptions are necessary for the analysis?
Exhibit 1-45
shows the results from analysis of the five unsignalized intersections. You can click
here to see the five datasets. Additional information necessary
to this analysis included assumptions regarding the
peak hour factor, heavy
vehicle percentages, and geometry.
|
Exhibit 1-45.
Intersection Delays
by Approach and Movement
(Click
here for Datasets) |
|
Intersection |
Delays by Approach
(sec/veh) |
|
East |
West |
North |
South |
|
LTR |
LTR |
L |
TR |
L |
TR |
|
#1 (North) |
22.8 |
19.6 |
8.7 |
0.0 |
9.2 |
0.3 |
|
#2 |
26.4 |
24.3 |
8.9 |
0.1 |
9.2 |
0.4 |
|
#3 |
32.0 |
25.9 |
9.1 |
0.7 |
9.1 |
0.3 |
|
#4 |
24.6 |
22.7 |
9.1 |
0.3 |
8.9 |
0.2 |
|
#5 (South) |
22.9 |
18.6 |
9.0 |
0.2 |
8.8 |
0.1 |
You probably recall
that the HCM unsignalized intersection analysis procedure assumes the Rank
1 through and right-turning movements on the major street don't yield to
any other movements. Why, then, is there a small amount of delay reported
in Exhibit 1-45 for these movements (NB through/right and SB
through/right)? The answer lies in the fact that, on this particular
two-lane highway, no separate lane is provided for vehicles turning left
from the major street onto the minor streets. When no left-turn pocket is
provided on the major street, a delayed left-turn vehicle will
occasionally block the Rank 1 vehicles behind it. The HCM procedure
accounts for this delay to Rank 1 vehicles, as shown in Exhibit 1-45.
For
the purpose of this sub-problem, we have assumed the default values presented
in Chapter 17 for unsignalized intersections.
In addition to these default values, we used the intersecting volumes
shown in
Exhibit 1-44, a PHF of 0.88, 10% trucks, and
flares of 2, 3, 2, 1,
and 1 vehicle at intersections 1-5 respectively
based on geometric data collected in the field.
[ Back ] [
Continue ] to
sub-problem 5c
