|
Sub-problem 3a - Page 13 of 13 |
ID# C403A13 |
Sub-problem 3a: Weaving Analysis
Just upstream, on
I-787NB, there is a two-lane off- ramp, which acts as a lane drop. We
examined the idea of maintaining that third lane through the weaving
segment, having the effect of adding a lane. The analysis results are
presented in Exhibit 4-57.
|
Exhibit 4-57. Effects of Lane Addition at Location E |
|
# of Lanes |
Ww |
Wnw |
Sw
mph |
Snw
mph |
S
mph |
Density
pcpmpl |
LOS |
Operation type |
|
3 |
4.61 |
0.88 |
23.02 |
38.97 |
27.87 |
44.99 |
F |
Constrained |
|
4 |
3.49 |
0.6 |
25.02 |
43.06 |
30.45 |
30.89 |
D |
Constrained |
You can see that the
impacts of the lane addition are significant. The LOS improves from F to D.
If the lane addition also increases the free flow speed on the freeway, that
would further improve the LOS to C.
The weave at location
E has shown the importance of considering multiple time periods, the effects
of the free flow speed and peak hour factors, and the importance of
geometric design in a weaving segment.
Weaving Segment D
The weaving movements at D are complex. There is an upstream merge on the
on-ramp and a lane drop in the middle of the weaving section. As a result,
this weaving segment will be thoroughly examined in Sub-problem 2c.
Weaving
Segment M
The weaving movements at Location M are also not traditional. The
location is a collector/distributor road located on the south side of Route
7. There is single through lane with an additional lane between the
I-787SB/Route 7EB on-ramp and the Route 7EB/I-787NB off-ramp. This section
will be discussed in detail in Sub-problem 2d.
[
Back ] [
Continue ] to Sub-Problem
3b
