TECHNICAL MEMORANDUM Introduction - Arlingtonva
3914 Centreville Road Suite 330 Chantilly, VA 20151 703.787.9595
TECHNICAL MEMORANDUM To: Rob Gibson
Arlington County
Bridget Obikoya From: Christopher M. Tacinelli, P.E. Felice B. Brychta, P.E. Jahid R. Russel
Date: June 1, 2012 Subject: Response to Comments ‐ RUID # 12784, Plan# Arlington SP 105, PenPlace
Introduction This memorandum addresses the comments received for RUID # 12784, Plan# Arlington SP 105, PenPlace in Arlington County, Virginia. Each comment is presented in italics with the response in bold immediately following. 1.
12th Street cross section needs to be revised to show the center platform in the cross section. The updated cross‐section has been included in the report.
2.
A protected northbound left turn lane is recommended for Army‐Navy Drive and Eads Street. Is there enough width for the left turn lane? The northbound approach was measured to be 25 feet wide at the intersection, which is wide enough to accommodate a left turn lane. In fact, currently the approach operates as a de‐facto left and thru‐right lane. This modification would involve restriping the approach without widening.
3.
Modifications to signal timings are generally acceptable to Arlington County as long as the cycle length is not changed. At the intersections with proposed signal retiming, the cycle length has not been changed.
4.
Confirm lane configuration for intersection 3, 8, 9 and 12. The lane configuration for Intersection #3 (Eads St. and Army Navy Dr.) shown in the TIA matches the Synchro files obtained from Arlington County and field conditions. The lane configuration shown in the TIA for intersection #8 (Hayes St. and 12th St.) includes an additional westbound right turn bay which is different from Arlington County Synchro files, but is how this approach currently operates in the field. The lane configuration at Intersection #9 (15th St. and Fern St.) has been modified from Arlington County Synchro files but reflects how the intersection operates in the field. At Intersection #12 (15th St. and Rte 1 NB Ramps) the lane configuration used in the TIA matches the Synchro files obtained from the County and the way this approach operates in the field.
Transportation Planners and Engineers
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Response to Comments for RUID # 12784, Plan# Arlington SP 105, PenPlace
Page 2
June 1, 2012
5.
Conduct additional turning movement counts at intersections #2, #3, #9, and #10 (Army Navy, 15th Street, Fern and Eads). New turning movement counts were conducted at these four intersections in March 2012. Additional counts were also conducted at the intersections of Army Navy Drive and S. Eads Street and 15th Street and S. Fern Street in May 2012 for comparison purposes. Generally the 2012 volumes were found to be consistent with or slightly lower than the 2010 volumes. A comparison of the 2010 volumes from the TIA and the new 2012 raw count volumes are included in Table 1 at the end of this memorandum. A cordon analysis was also conducted which shows that traffic entering and exiting the cordon area has decreased between 2010 and 2012, with the exception of the AM outbound volumes which have increased by 4.5%. A figure showing the cordon area and a summary of the results is included in Table 3 at the end of this memorandum. Since the existing 2010 volumes in the TIA were increased based on a 1% growth rate per year for future scenarios, and since this comparison shows that the 2012 and 2010 volumes are generally consistent, it would indicate that the 1% growth rate per year assumed in the TIA is actually conservative.
6.
Provide more information on the percentage of trips expected to use I‐395 to/from the south. Approximately 15% of the site generated traffic is anticipated to travel to/from the site via I‐395 to the south. This equates to approximately 135 trips during the AM peak hour and 153 trips during the PM peak hour. Average daily traffic volumes obtained from VDOT for I‐395 between S. Glebe Road and Washington Boulevard show approximately 199,000 daily volume in 2010 (2011 data is not yet available from VDOT). Approximately 0.072 of the daily traffic on I‐395 occurs during the peak hour (based on the VDOT data), which equates to approximately 14,328 trips during the peak hours. Therefore, the trips generated by the PenPlace site will equate approximately 1.0% of the I‐395 traffic during the AM and PM peak hours. Additionally, queuing on the northbound I‐395 ramp (Ramp 8C) to Pentagon City was considered. This ramp curves to intersect with Army Navy Drive, forming the southbound approach to the Army Navy Drive/S. Hayes Street intersection. At the off‐ramp from I‐395 to Army Navy Drive, there is over 2,000 feet from the stop bars at Army Navy Drive to the through lanes along I‐395. The 95th percentile queue for the southbound left turn was found to be 754 feet, leaving over 1,200 feet from the end of the projected queue to the through lanes of I‐395. Therefore, the queues at this intersection are not expected to impact the through lanes of I‐395 or the diverge operation.
7.
Provide a comparison of the traffic growth assumed with traffic generated by Metropolitan Park 4/5 and Pentagon Centre Phase 1. The TIA assumed a growth rate of 1.0% per year plus the Met Park 2/3 projects as background developments. Other TIA’s completed within the area in recent years include growth rates of 0.5% or less. The PenPlace study included a higher growth rate of 1.0% to account for any possible redevelopment beyond the area immediately surrounding the PenPlace site. A comparison of the background traffic volumes determined in the TIA (assuming 1.0% growth per year plus the Met Park 2/3 projects) with a growth rate of 0.5% per year plus site generated trips for Met Park 4/5 and Phase 1 of the Pentagon Centre development was completed. It was assumed that Metropolitan Park 4/5 will include 734 apartments with a mode split reduction of 40%. The site trips for Pentagon Center Phase I were based on
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Response to Comments for RUID # 12784, Plan# Arlington SP 105, PenPlace
Page 3
June 1, 2012
the traffic study completed by Wells and Associates. The comparison shows that in general, the background volumes projected in the TIA are similar to or higher than those determined using the 0.5% growth rate plus Met Park 4/5 and Phase 1 of Pentagon Centre. Since the TIA provides a more conservative estimate of traffic volumes, the original background volumes in the TIA have not been revised. The comparison is shown in Table 2 at the end of this memorandum. 8.
Arlington County predicts a 0.5% annual mode shift by 2020. The estimate of an additional 0.5% mode shift for existing trips as well as trips expected to be generated by future developments were not included and therefore the results of the TIA should be considered to show a “worst‐case” analysis. Additional discussion will be needed with the County to better understand the projections if and how they should be applied to existing and future traffic volumes in the vicinity of the site.
Gorove/Slade
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Response to Comments for RUID # 12784, Plan# Arlington SP 105, PenPlace
Page 4
June 1, 2012
Table 1: 2010 and 2012 Peak Hour Turning Movement Comparison 2010 Intersection
2012
Annual Growth
AM
PM
AM
PM
AM
PM
38
142
49
129
13.6%
-4.7%
Thru
681
626
955
537
18.4%
-7.4%
Right
196
95
144
155
-14.3%
27.7%
Left
56
124
51
165
-4.6%
15.4%
Thru
25
115
26
95
2.0%
-9.1%
Right
35
117
26
90
-13.8%
-12.3%
Left
108
66
89
43
-9.2%
-19.3%
Army Navy Dr and S Fern St Left EB
NB
WB
SB Intersection
Thru
531
863
514
685
-1.6%
-10.9%
Right
24
256
39
147
27.5%
-24.2%
Left
80
33
67
25
-8.5%
-13.0%
132
72
111
45
-8.3%
-20.9%
10.2%
-1.7%
4.5%
-7.9%
Thru Right
89
120
108
116
Total
1,995
2,629
2,179
2,232
AM+PM Combined
4,411
4,624
-2.3%
Army Navy Drive and S Eads St Left EB
NB
WB
Intersection AM+PM Combined
Gorove/Slade
440
447
441
54.6%
0.1%
Thru
270
117
289
197
3.5%
29.8%
Right
123
215
148
182
9.7%
-8.0%
Left
147
337
140
241
-2.4%
-15.4%
Thru
126
293
154
147
10.6%
-29.2%
Right
24
6
14
20
-23.6%
82.6%
Left
45
28
9
36
-55.3%
13.4%
Thru
281
776
229
536
-9.7%
-16.9%
Right
38
289
57
213
22.5%
-14.1%
39
4
32
12
-9.4%
73.2%
Thru
380
108
224
95
-23.2%
-6.2%
Right
188
144
282
157
22.5%
4.4%
Total
1,848
2,757
2,025
2,277
4.7%
-9.1%
Left SB
187
4,605
4,302
-3.3%
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Response to Comments for RUID # 12784, Plan# Arlington SP 105, PenPlace
Page 5
June 1, 2012
2010 Intersection
2012
Annual Growth
AM
PM
AM
PM
16
49
22
99
Thru
422
344
490
461
Right
14
49
36
Left
19
33
Thru
70
81
Right
90
Left
44
AM
PM
15th St and S Fern St Left EB
NB
17.3%
42.1%
7.8%
15.8%
36
60.4%
-14.3%
15
23
-11.1%
-16.5%
85
105
10.2%
13.9%
46
100
34
5.4%
-14.0%
105
41
70
-3.5%
-18.4%
Thru
351
646
327
753
-3.5%
8.0%
Right
217
181
223
199
1.4%
4.9%
Left
90
235
110
221
10.6%
-3.0%
SB
Thru
51
167
34
137
-18.4%
-9.4%
Right
5
42
18
49
89.7%
8.0%
Intersection
Total
1,389
1,978
1,501
2,187
4.0%
5.2%
WB
AM+PM Combined
3,688
3,367
4.7%
15th St and S Eads St Left EB
NB
38
41
33
35
-6.8%
-7.6%
Thru
502
514
524
459
2.2%
-5.5%
Right
60
37
48
64
-10.6%
31.5%
Left
64
85
71
74
5.3%
-6.7%
Thru
193
270
234
217
10.1%
-10.4%
Right
106
146
198
113
36.7%
-12.0%
65
205
94
221
20.3%
3.8%
502
856
363
713
-15.0%
-8.7%
Right
149
188
100
139
-18.1%
-14.0%
Left
129
95
146
86
6.4%
-4.9%
Thru
257
252
186
221
-14.9%
-6.4%
Right
41
79
26
47
-20.4%
-22.9%
Total
2,106
2,768
2,023
2,389
-2.0%
-7.1%
Left WB
SB Intersection
Thru
AM+PM Combined
4,412
4,874
-4.9%
12th Street and Fern Street EB NB SB Intersection AM+PM Combined Gorove/Slade
Left
28
52
42
73
22.5%
18.5%
Right
41
112
71
122
31.6%
4.4%
31
38
40
57
13.6%
22.5%
Thru
211
183
264
249
11.9%
16.6%
Thru
105
305
83
300
-11.1%
-0.8%
Right
50
36
27
34
-26.5%
-2.8%
Total
466
726
527
6.3%
7.2%
Left
1,192
835 1,362
6.9% www.goroveslade.com
Response to Comments for RUID # 12784, Plan# Arlington SP 105, PenPlace
Page 6
June 1, 2012
2010 Intersection
2012
Annual Growth
AM
PM
AM
PM
AM
PM
Left
56
92
72
69
13.4%
-13.4%
Right
61
122
45
76
-14.1%
-21.1%
Thru
294
368
239
280
-9.8%
-12.8%
Right
104
60
95
69
-4.4%
7.2%
Left
208
66
160
62
-12.3%
-3.1%
Thru
353
293
243
294
-17.0%
0.2%
Total
1,076
1,001
854
850
-10.9%
-7.9%
12th Street and S Eads St WB NB SB Intersection AM+PM Combined
2,077
1,704
-9.4%
2010 volumes are taken from the Original TIA Figure 13 (balanced) 2012 volumes are unbalanced raw counts
Gorove/Slade
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Response to Comments for RUID # 12784, Plan# Arlington SP 105, PenPlace
Page 7
June 1, 2012
Table 2: Future Background (2020) Traffic Volume Comparison
Intersection
Original TIA
Alternate
(1.0% Growth/Yr. + Met Park 2/3)
(0.5% Growth/Yr. + Met Park 2,3,4,5 + Ph.1 Pentagon Center)
Difference
AM
PM
AM
PM
AM
PM
Left
42
157
40
149
-2
-8
Thru
670
666
633
632
-37
-34
Right
222
120
220
143
-2
23
Left
75
150
91
154
16
4
Thru
43
143
68
151
25
8
Right
43
134
50
131
7
-3
Left
121
80
151
82
30
2
Army Navy Dr and S Fern St EB
NB
WB
SB Intersection
Thru
563
905
534
858
-29
-47
Right
21
271
19
257
-2
-14
Left
67
29
63
28
-4
-1
Thru
153
100
167
130
14
30
Right
98
133
94
126
-4
-7
Total
2,118
2,888
2,130
2,841
12
-47
Left
211
491
211
470
0
-21
Thru
298
129
284
123
-14
-6
Right
32
205
25
193
-7
-12
Left
132
311
125
293
-7
-18
Army Navy Drive and S Eads St EB
NB
WB
SB Intersection
Gorove/Slade
Thru
150
335
163
330
13
-5
Right
27
7
25
6
-2
-1
Left
50
31
47
29
-3
-2
Thru
311
857
299
816
-12
-41
Right
42
319
40
304
-2
-15
Left
43
4
41
4
-2
0
Thru
425
132
411
155
-14
23
Right
210
166
228
164
18
-2
Total
1,931
2,987
1,899
2,887
-32
-100
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Page 8
June 1, 2012
Intersection
Original TIA
Alternate
(1.0% Growth/Yr. + Met Park 2/3)
(0.5% Growth/Yr. + Met Park 2,3,4,5 + Ph.1 Pentagon Center)
Difference
AM
PM
AM
PM
AM
PM
Left
20
58
22
68
2
10
Thru
466
380
444
362
-22
-18
Right
15
54
15
52
0
-2
Left
21
36
20
35
-1
-1
Thru
79
97
83
106
4
9
Right
99
51
95
48
-4
-3
Left
49
116
46
110
-3
-6
15th St and S Fern St EB
NB
WB
SB Intersection
Thru
388
714
376
700
-12
-14
Right
241
215
239
207
-2
-8
Left
97
224
97
231
0
7
Thru
61
190
72
211
11
21
Right
9
49
13
50
4
1
Total
1,545
2,184
1,522
2,180
-23
-4
15th St and S Eads St EB
NB
WB
SB Intersection
Left
43
46
41
44
-2
-2
Thru
536
513
520
506
-16
-7
Right
83
59
116
79
33
20
Left
82
124
87
179
5
55
Thru
217
308
210
312
-7
4
Right
117
161
111
153
-6
-8
Left
72
227
68
215
-4
-12
Thru
549
942
538
921
-11
-21
Right
173
219
165
209
-8
-10
Left
144
106
137
101
-7
-5
Thru
298
291
297
286
-1
-5
Right
45
88
43
84
-2
-4
Total
2,359
3,084
2,333
3,089
-26
5
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Response to Comments for RUID # 12784, Plan# Arlington SP 105, PenPlace
Page 9
June 1, 2012
Figure 1: Cordon Area
Table 3: Cordon Area Summary* Difference (2010 - 2012)
2010
2012
Inbound
3,535
3,507
28
Outbound
2,828
3,088
-260
(4.5%)
Inbound
4,126
3,714
412
(-5.1%)
Outbound
4,450
4,076
374
(-4.3%)
AM (-0.4%)
PM
*See Attached Table for Detailed Movements Gorove/Slade
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Response to Comments for RUID # 12784, Plan# Arlington SP 105, PenPlace
Page 10
June 1, 2012
2010
2012
Annual Growth
AM
PM
AM
PM
Inbound - EB
877
721
1,099
692
11.9%
-2.0%
Inbound - SB
221
192
219
161
-0.5%
-8.4%
Outbound - NB
81
239
77
260
-2.5%
4.3%
Outbound - WB
555
1,119
553
832
-0.2%
-13.8%
Inbound - WB
326
804
238
572
-14.6%
-15.7%
Inbound - SB
419
112
256
107
-21.8%
-2.3%
Outbound - EB
457
557
736
638
26.9%
7.0%
Outbound - NB
150
299
168
167
5.8%
-25.3%
Inbound - EB
436
393
526
497
9.8%
12.5%
Inbound - NB
160
127
185
139
7.5%
4.6%
Outbound - WB
395
751
368
823
-3.5%
4.7%
Outbound - SB
56
209
52
186
-3.6%
-5.7%
Intersection
AM
PM
Army Navy Dr and S Fern St
Army Navy Drive and S Eads St
15th St and S Fern St
15th St and S Eads St Inbound - NB
257
355
305
291
8.9%
-9.5%
Inbound - WB
651
1,044
463
852
-15.7%
-9.7%
Outbound - EB
562
551
572
523
0.9%
-2.6%
Outbound - SB
386
347
332
307
-7.3%
-5.9%
Inbound - EB
69
164
113
195
28.0%
9.0%
Outbound - WB
81
74
67
91
-9.1%
10.9%
Inbound - WB
117
214
117
145
0.0%
-17.7%
Outbound - EB
312
126
255
131
-9.6%
2.0%
12th Street and Fern Street
12th Street and S Eads St
2010 volumes are taken from the Original TIA Figure 13 (balanced) 2012 volumes are unbalanced raw counts 15th St & Fern St, Army Navy Dr & Eads St, 12th St & Fern St, and 12th St & Eads St are counted in May 2012; Army Navy Dr & Fern St and 15th St & Eads St are counted in March 2012
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