|
| |
|
Sub-problem 3b - Page 4 of 10 |
ID# C403B04 |
Sub-problem 3b: Ramps
Checking the Ramps
The middle section of the ramp is a roadway that looks like a small, basic
freeway section of one or more lanes. This section usually doesn’t cause
capacity problems, but there could be if the curve radii are small or there
are changes in the number of lanes. It’s important to analyze the ramp to
assure it functions properly.
We need to check the
various short sections of ramp roadway within the interchange to assure they
all have enough capacity to handle the traffic they have to carry. This is
done by checking that there are enough lanes that are straight enough (i.e.,
have sufficient radii) that the geometry won’t interfere with the capacity.
Exhibit 4-58
contains the AM and PM peak hour ramp volumes for each of the ramps. It also
contains the ramp speeds, the HCM suggested capacities, and the calculated
v/c ratios.
|
Exhibit
4-58. Operational Analysis of the Route 7/I-787 Ramps |
|
Ramp
Location |
# of
Lanes |
Speed
mph |
Volume |
HCM
Capacities |
v/c |
|
AM |
PM |
AM |
PM |
|
Route 7 EB to
I-787 SB |
1 |
30 |
1,865 |
785 |
1,900 |
0.982 |
0.414 |
|
Route 7 EB to
I-787 NB |
1 |
25 |
155 |
300 |
1,900 |
0.082 |
0.157 |
|
Route 7 WB to
I-787 SB |
1 |
40 |
1,420 |
745 |
2,000 |
0.711 |
0.371 |
|
Route 7 WB to
I-787 NB |
1 |
40 |
125 |
225 |
2,000 |
0.063 |
0.114 |
|
I-787 SB to
Route 7 WB |
1 |
35 |
340 |
290 |
2,000 |
0.171 |
0.146 |
|
I-787 SB to
Route 7 EB |
1 |
25 |
180 |
150 |
1,900 |
0.095 |
0.079 |
|
I-787 NB to
Route 7 WB |
1 |
25 |
715 |
1,870 |
1,900 |
0.376 |
0.984 |
|
I-787 NB to
Route 7 EB |
2 |
45 |
550 |
1,015 |
4,100 |
0.134 |
0.247 |
|
|
