McMAHON ASSOCIATES
300 Myles Standish Boulevard | Taunton, MA 02780
p 508-823-2245 | f 508-823-2246
www.mcmtrans.com
PRINCIPALS
MEMORANDUM DRAFT
TO: Steve McLaughlin, MassDOT Joseph W. McMahon, P.E.
Joseph J. DeSantis, P.E., PTOE
John S. DePalma
William T. Steffens
Casey A. Moore, P.E.
Gary R. McNaughton, P.E., PTOE
ASSOCIATES
John J. Mitchell, P.E.
Christopher J. Williams, P.E.
John F. Yacapsin, P.E.
FROM: Gary McNaughton, P.E., PTOE SUBJECT: Casey Overpass Project ‐ Existing Traffic Analysis and Future Volumes DATE: September 22, 2011 Introduction This memorandum has been prepared to summarize the Existing 2010 traffic analysis and Future No Build 2035 traffic projections for the Casey Overpass project. The information contained within this memorandum has been presented to the Working Advisory Group (WAG) and the public. Study Area The extensive study area includes eighteen intersections along major roadways in the vicinity of the Casey Overpass as depicted in Figure 1. The signalized intersections in the study area include the following: • Hyde Park Avenue /Walk Hill Street • Hyde Park Avenue /Ukraine Way • Hyde Park Avenue/Tower Street • Washington Street/MBTA Busway #1/Fitzgerald Parking Lot • Washington Street/New Washington Street/Arborway Westbound Surface Rd/Orchard Hill Road • New Washington Street/Southwest Corridor Park • Washington Street/Ukraine Way • Washington Street/MBTA Busway #2/Arnold Arboretum West Gate • Washington Street/ South Street/MBTA Busway #2 • South Street/New Washington Street/Arborway Ramps/MBTA Busway #3 • Morton Street (Route 203)/Cemetery Road The unsignalized intersections in the study area include: • Arborway Eastbound Surface Rd/Orchard Hill Road • Arborway Eastbound Surface Road/Court House Parking Area/Morton Street • Washington Street/MBTA Repair Facility Corporate Headquarters: Fort Washington, Pennsylvania
Serving the East Coast from 10 offices throughout the Mid-Atlantic, New England, and Florida
Steve McLaughlin September 23, 2011 •
•
•
Washington Street/MBTA Busway #2 South Street/Arborway West Surface Road Arborway/Morton Street/Forest Hills Street Rotary (Shea Circle) Page 2
DRAFT
Steve McLaughlin September 23, 2011 Page 4 DRAFT Existing Traffic Conditions The existing traffic conditions was previously discussed in a memorandum that highlights the data collection efforts and existing traffic highlights. The existing traffic highlights memorandum was dated November 1, 2010 and is posted on the project website. The traffic existing volume figures are included in the appendix accompanying this memorandum. Existing Operations ‐ Vehicular This section presents the results of the vehicular traffic analysis conducted based on current traffic volumes within the study area. Existing operations for alternate modes, including pedestrian, bicycle and transit, will be presented in a subsequent memorandum that discusses future traffic operations under the proposed alternatives. As part of the design and analysis for this project, Synchro networks of the study area were prepared for weekday morning and afternoon peak periods for both existing and future vehicular traffic conditions. The Synchro analyses were based on a network received from the Boston Transportation Department (BTD). The BTD Synchro network was updated to reflect current vehicular, pedestrian, and bicycle volumes, then calibrated based on BTD signal timing plans and field observations of intersection geometry, roadway widths, lane assignments, signal timings, overall operations and queuing. Based on the methodologies from the 2000 Highway Capacity Manual, detailed capacity/level‐of‐
service analyses were completed for the existing peak hour volumes at the study area intersections. Level‐of‐service (LOS) is a term used to describe the quality of traffic flow on a roadway or intersection for a particular point in time. Level of service is a measure of driver comfort under a given set of roadway and traffic conditions and is reflective of travel delay, travel speed, and congestion. Operating levels of service are reported on a scale of A to F with A representing the best conditions (with little or no delay) and F representing the worst operating conditions (long delays). LOS D is generally considered acceptable in this region and LOS E and F may be acceptable for certain movements. The overall vehicular capacity/level‐of‐service analysis results for the existing weekday morning and afternoon peak hours at the signalized study area intersections are presented in Table 1. Results for individual movements within the intersections are presented in the appendix to this memorandum. Steve McLaughlin September 23, 2011 Page 5
DRAFT
Table 1 Existing 2010 Vehicular Traffic Operations ‐ Signalized Intersections
Weekday AM Peak Hour
Intersection
1
2
Movement LOS Delay
V/C3
Weekday PM Peak Hour
LOS Delay
V/C
South Street/New Washington Street/Ramps
Overall
D
50.4
1.3
E
68.4
0.8
South Street/Washington Street/MBTA Busway
Overall
E
65.0
0.9
D
38.8
1.0
Washington St/MBTA Busway/Ped Signal
Overall
A
2.2
0.3
A
1.1
0.3
Washington Street at Ukraine Way
Overall
C
23.6
0.8
C
26.8
1.0
Hyde Park Avenue at Walk Hill Street
Overall
C
26.6
0.8
C
26.9
1.0
Hyde Park Avenue at Ukraine Way
Overall
D
37.5
0.8
C
20.4
0.8
Washington Street at Tower Street
Overall
B
16.0
0.6
A
9.5
0.5
Washington Street at Fitzgerald Lot
Overall
A
9.9
0.4
B
10.6
0.6
Washington Street at New Washington Street
Overall
D
48.1
1.0
C
34.9
0.9
Morton Street (Route 203) at Cemetery Road
Overall
C
29.0
1.0
E
58.7
1.4
1
Level‐of‐Service
2
Average vehicle delay in seconds
3
Volume to capacity ratio
Currently, all signalized intersections in the project study area are shown to operate at an overall LOS D or better, except for the intersections of South Street/New Washington/Arborway Ramps (LOS E during the weekday afternoon peak hour), South Street/Washington Street/MBTA Busway (LOS E during the weekday morning peak hour) and the intersection of Morton Street/Cemetery Road (LOS E during the weekday afternoon peak hour). There are also capacity constraints at a number of the intersections during the peak periods with volume to capacity ratios (v/c) equal to or greater than 1.0, which indicates that the volume of traffic is greater than the theoretical capacity for that movement. While level‐of‐service results provide an overview of traffic operations, in the complex urban transportation network within this study area, many other factors, such as queuing, signal coordination, and curbside conflicts can result in actual operations that are worse than those Steve McLaughlin September 23, 2011 Page 6 DRAFT represented by the level‐of‐service results. Based on field observations and discussions with the community, traffic operations within this study area are affected by queue spill back between closely spaced intersections, pick‐up/drop‐off conflicts in the vicinity of the MBTA Forest Hills Station, and poor signal coordination. These factors negatively affect the overall operations at several key intersections in the study area. The greatest factor affecting vehicle operations within this study area is queue spillback from the closely spaced intersections along South Street. There are a total of three signalized intersections within a distance of less than 300 feet and the queuing for these intersections often affects overall operations. This situation is occasionally exacerbated by the midblock pedestrian signal located less than 200 feet east of the intersection of South Street, New Washington, and the westbound on‐ramp. This system of four closely spaced intersections is extremely difficult to maintain appropriate signal coordination and manage queues within the short distances separating the signals. The queuing analysis results are presented graphically in Figure 2 and the detailed queue analysis summary table is included in the appendix to this memorandum. As shown in this graphic the queue lengths can be excessive and extend through adjacent intersections. This interaction of the queues, combined with high vehicle delays, creates the poor overall operations that are currently experienced on the study area roadways. XX
XX
Steve McLaughlin September 23, 2011 Page 8
DRAFT
Future (2035) Traffic Volume Projections To properly assess long‐term infrastructure alternatives, existing traffic volumes are typically projected 25 years into the future to assure that the designs will serve the needs for years to come. For the Casey Overpass project, volumes were projected to the year 2035 through a combination of regional traffic volume projections from the Central Transportation Planning Staff’s (CTPS) regional model and local development projects identified by the Boston Redevelopment Authority (BRA). The CTPS Regional Model is a multi‐modal model (vehicles, peds, transit) based upon existing volume data and socio‐economic data broken down into “Traffic Analysis Zones,” (TAZ). The model projects traffic volumes based on this data to project overall regional travel demands. The model then considers existing roadway infrastructure and known roadway infrastructure changes to project volumes on individual roadway segments. Through the application of the CTPS model, traffic increases were calculated by roadway link for the 25‐year projection to the future‐year of 2035. In addition to regional traffic growth projected with the CTPS model, specific development parcels were identified by the BRA and were incorporated in the development of the future year 2035 traffic volumes. The specific development parcels and traffic projection methodology are presented later in this memorandum. CTPS Model Calibration To confirm and if necessary calibrate the regional traffic model, McMahon collected license plates data for traffic on the Casey Overpass between 7:30‐8:30 AM and 4:30‐5:30 PM on Thursday, November 4, 2010. With access to the Registry of Motor Vehicles (RMV) records, CTPS determined the addresses for each recorded license plate, which can generally be assumed to be the vehicle “origin.” The license plate origins were compiled and compared to the origins exhibited in the regional traffic model and generally confirmed the data within the regional model. For the Casey Overpass, the license plate data revealed the following origin results: Steve McLaughlin September 23, 2011 Page 9
DRAFT
Table 2 Origins of Existing Vehicles Using the Casey Overpass
AM
PM
Model
License
Model
License
Community
Results
Survey
Results
Survey
Boston
52%
48%
46%
44%
Quincy
6%
5%
6%
7%
Milton
4%
6%
4%
6%
Newton
6%
4%
9%
4%
Brookline
9%
5%
9%
4%
Other
23%
33%
26%
35%
Total
100%
100%
100%
100%
CTPS Study Area Projections The CTPS regional traffic model is based upon socio‐economic data by “Traffic Analysis Zone,” (TAZ) and projections were made for the year 2035. To assess the development activity with the area surrounding the Casey Overpass, CTPS provided the population and employment projections for the TAZ’s within the project area. A review of the socio‐economic data for the TAZs closest to the Casey Overpass, TAZs 309, 310, 311, 347, 348, and 349, reveals an expected two‐percent increase in population and a one percent decrease in employment between 2010 and 2035. Traffic growth for each roadway link in our study area was estimated by CTPS and applied to the Existing 2010 traffic volumes. Alternative modes of transportation including, pedestrians, bicyclists and transit were estimated to grow approximately ten percent by 2035 based on CTPS projections and local development potential. City of Boston Local Development Parcels In addition to the regional model information provided by CTPS, this study considered potential local developments within the Forest Hills area that would affect vehicle, pedestrian, bicycle, and transit volumes. Based upon coordination with BRA and BTD, eight potential development parcels in the study area were identified to be included in future traffic volumes. Steve McLaughlin September 23, 2011 Page 10 DRAFT These parcels, shown in Figure 3 and summarized in the following table, were also identified in the Forest Hills Improvement Initiative. Approximately 20% of the development and related traffic generation from these parcels was already included in the CTPS regional model, as evident by the population and employment projections from the model. Many factors will determine the actual development and resulting travel demands for the parcels that were identified by BRA. Given the uncertainty in the level of development that will occur and the likelihood of an increase in alternate modes of travel with the increased development density, this study incorporates approximately 80% of the volumes of trips expected to be generated by these parcels. Table 3: Forest Hills Improvement Initiative Parcel Estimates Parcel Name Housing Units Office Area (sq. ft) Retail Area (sq. ft) MBTA Parcel U 96 n/a 3,200 MBTA Parcel V n/a 6,418 3,209 MBTA Parcel W n/a 15,428 10,386 MBTA Parcel S n/a 135,200 33,600 Fitzgerald Parking Lot 64 n/a 12,000 Arborway Yard 128 100,000 28,000 3615 Washington St n/a 48,000 24,000 3529 Washington St. 30 28,000 17,600 The trip generation of each parcel was first estimated using the trip generation rates for the appropriate land use code as published in ITE’s Trip Generation Manual, 8th Edition, for daily, AM peak hour, and PM peak hour volumes. The trip generation was then converted to mode‐type trips using mode share ratios developed by BTD, with mode types including auto, transit, and walking trips. The distribution of the trips from the Forest Hills Initiative development parcels was similarly based upon standards developed by BTD for each area of the City. The volumes generated by each development parcel were assigned to the study area network based on the traffic generation, mode split, and distribution standards developed by BTD. Steve McLaughlin September 23, 2011 Page 12 DRAFT Future No Build 2035 Traffic Volumes The traffic volume projections developed from the CTPS model were combined with the specific local development projects to represent the 2035 volumes. The volumes from the CTPS model were applied to individual roadway segments and the intersection turning movements were adjusted to reflect the link growth and where appropriate, adjacent intersection volumes were balanced. Traffic volumes from the City of Boston local development parcels were then superimposed on the street network to calculate the future 2035 traffic volumes. The No Build 2035 projected traffic volumes for vehicles, pedestrians and bicycles are presented in the appendix of this memo and have been posted on the project website under Future Traffic Volumes. Next Steps This memorandum presented the existing traffic operations and the future year, 2035, projected traffic volumes. The future volumes will be used to assess the alternatives that are under consideration for the Casey Overpass project. A subsequent technical memorandum will be prepared to present the traffic analysis results for the 2035 traffic volumes for each alternative for the Casey Overpass project. The future operations technical memorandum will discuss the urban facilities LOS, which provides an overall traffic operations assessment for all roadway users, including pedestrian, bicycle and transit users. APPENDIX Capacity Analysis Summary
Casey Overpass
Boston, MA
DRAFT
Existing 2010
Weekday AM Peak Hour
Weekday PM Peak Hour
LOS1
Delay2
V/C3
LOS
Delay
V/C
Overall
F
A
E
D
F
B
D
F
D
C
C
E
A
A
A
278.2
1.4
64.8
41.6
85.5
17.4
50.4
243.2
36.8
24.0
29.5
65.0
2.5
1.7
2.2
1.3
0.3
0.8
0.9
0.9
0.2
1.3
0.9
0.3
0.8
0.5
0.9
0.3
0.2
0.3
F
F
F
D
D
C
E
F
D
B
C
D
A
A
A
83
150
87.2
35.6
48.2
32
68.4
101
39.6
13.8
29.4
38.8
1.6
0.8
1.1
0.81
0.64
0.77
0.78
0.62
0.52
0.81
0.97
0.34
0.45
0.64
0.97
0.2
0.29
0.29
Intersection
Movement
South Street at
EB
LT
New Washington Street/
Arborway Ramps
R
WB
LTR
NB
LTR
SB
L
TR
Overall
South Street at
EB
LR
Washington Street/
WB
LR
MBTA Busway#2
NB
LT
SB
TR
Overall
Washington Street at
NB
TR
MBTA Busway#2
SB
LR
Washington Street at
WB
L
E
59.5
0.7
D
44.8
0.75
R
B
17.9
0.8
B
11.5
0.67
NB
TR
SB
L
C
C
B
C
B
C
E
A
C
D
C
D
D
D
D
C
B
B
B
A
B
A
A
E
E
B
F
C
C
A
D
A
D
B
C
C
20.1
25.8
18.4
23.6
17.7
31.1
68.6
6.1
26.6
54 8
54.8
23.4
37.0
40.3
37.5
53.0
26.7
16.0
10.6
16.0
0.0
14.0
2.7
9.9
62.2
77.9
10.8
86.6
26.4
34.4
2.2
48.1
8.9
35.4
17.4
33.6
29.0
0.4
0.5
0.2
0.8
0.8
0.7
0.6
0.2
0.8
08
0.8
0.6
0.87dl
0.5
0.8
0.6
0.2
0.4
0.2
0.6
0.0
0.4
0.3
0.4
0.7
0.9
0.3
1.0
0.7
0.6
0.1
1.0
0.4
1.0
0.0
0.7
1.0
B
D
A
C
F
C
C
A
C
E
B
B
B
C
E
C
B
A
A
C
A
A
B
E
E
A
E
A
C
A
C
B
B
B
F
E
17.2
52.4
8.6
26.8
80.3
33.7
32.4
4.8
26.9
55 6
55.6
19.4
14.2
18.4
20.4
58.6
34.1
14.3
2.6
9.5
34.6
9
9.6
10.6
60.4
73.2
9.9
59.9
5.5
31.8
1.9
34.9
19.4
13.1
15.9
230.5
58.7
0.35
0.97
0.29
0.97
1.0
0.5
0.8
0.5
1.0
0 78
0.78
0.76
0.99dl
0.74
0.78
0.34
0.23
0.37
0.52
0.52
0.26
0.53
0.59
0.59
0.68
0.82
0.35
0.87
0.48
0.61
0.18
0.87
0.82
0.64
0.03
1.43
1.43
Ukraine Way
T
Overall
Hyde Park Avenue at
WB
LR
Walk Hill Street
NB
TR
SB
L
T
Overall
Hyde Park Avenue at
EB
L
Ukraine Way
R
NB
LT
SB
TR
Overall
Washington Street at
EB
LR
Tower Street/MBTA Busway# WB
LR
NB
TR
SB
LT
Overall
Washington Street at
WB
LR
Fitzgerald Parking Lot/
NB
LTR
MBTA Busway#1
SB
LTR
Overall
Washington Street at
EB
L
Arborway WB Surface Road/
T
New Washington St/
Orchard Hill Road
R
WB
LTR
NB
LT SB
LT
R
Overall
Morton Street (Route 203)/
EB
LTR
Cemetery Road
WB
LTR
NB
LTR
SB
LTR
Overall
1
Level‐of‐Service
2
Average vehicle delay in seconds
3
Volume to capacity ratio
Queue Analysis Summary
Casey Overpass
Boston, MA
DRAFT
Existing 2010
Weekday AM Peak Hour
95th Queue
Weekday PM Peak Hour
2
50th Queue
95th Queue
LT
~76
#178
96
#174
R
0
0
0
66
211
#630
#205
157
368
76
#475
279
127
40
219
262
68
217
271
m#446
#223
370
267
#468
Intersection
Movement
South Street at
EB
New Washington Street/
50th Queue
1
MBTA Busway#2
SB
LR
148
163
80
102
265
33
146
203
81
36
Washington Street at
WB
L
117
m114
124
R
58
m196
60
48
NB
TR
144
225
132
196
SB
L
119
212
~324
#515
T
88
184
160
176
117
Arborway Ramps
WB
LTR
NB
LTR
SB
L
TR
South Street at
EB
LR
Washington Street/
WB
LR
MBTA Busway#2
NB
LT
SB
TR
Washington Street at
NB
TR
Ukraine Way
24
59
112
321
30
10
128
286
35
m15
137
Hyde Park Avenue at
WB
LR
14
0
~156
Walk Hill Street
NB
TR
395
484
217
281
SB
L
187
79
256
94
241
95
#263
114
T
Hyde Park Avenue at
EB
L
148
232
148
m144
R
104
224
89
m114
NB
LT
SB
TR
418
167
#768
308
116
447
m135
#655
m58
Ukraine Way
LR
35
88
29
Tower Street/MBTA BuswayWB
Washington Street at
EB
LR
11
43
25
65
NB
TR
SB
LT
255
50
0
18
0
393
138
0
#446
m91
256
36
243
42
53
104
61
153
29
187
Washington Street at
WB
LR
Fitzgerald Parking Lot/
NB
LTR
MBTA Busway#1
SB
LTR
Washington Street at
EB
Arborway WB Surface Road/
New Washington St/
Orchard Hill Road
L
139
182
134
202
T
164
#230
156
228
R
WB
LTR
NB
LT SB
LT
R
Morton Street (Route 203)/ EB
LTR
Cemetery Road
LTR
1
2
WB
NB
LTR
SB
LTR
50th Percentile Queue Length in feet
95th Percentile Queue Length, in feet
N/A Not Applicable
0
29
0
47
~253
137
151
0
74
~384
3
97
#336
324
192
24
132
#669
11
171
222
13
234
0
277
165
5
~418
286
39
323
30
371
228
15
#617