HomeMy WebLinkAboutAttach 5 TrafficCirAnlys byOmniomn .meQns
ENGiNEeRS ' PLANNERS
January 21, 2003 (revised)
Mr. Ray Kuzbari
Senior Traffic Engineer
City of Dublin
100 Civic Plaza
Dublin, CA 94568
Subject:
Focused Internal Traffic Circulation Analysis for the Phase 1 Avalon Bay
Transit Center Residential Developments in the City of Dublin
Dear Mr. Kuzbari:
This report outlines our findings with regard to internal traffic circulation within the Dublin
Transit Center located in east Dublin. Primarily, our analysis focuses on those intersections and
roadways located south of Dublin Boulevard within planned residential, office, and BART uses.
Based c~n land use information provided in the City's summary description of the Phase 1 Transit
Center project the following sections describe the development's trip generation, internal and
external (adjacent) intersection operation, and site specific vehicle access, circulation, and
parking.
A. Residential Development Trip Generation:
Residential Project Description
The residential parcels identified (with site plans) in Phase 1 development have been shown in
Fibre 1 and can be summarized as follows:
Site A2:
112 apartment units;
160 limited access garage spaces;
5 on-street parking spaces.
Site BI:
260 condominium/townhome units;
490 limited access garage spaces;
23 on-street parking spaces.
Site B2:
310 apartment/townhome units;
15,300 ksf retail;
458 limited access garage parking spaces;
47 public garage parking spaces (retail & guest);
33 on-street parking spaces.
ATTACHMENT
1901 Olympic Boulevard, Suite !20 · Walnut CreeP,, CA, 94596 - (925) 935-2230 fax: (925) 935-2247
ROSEVILLE REDDING VISALtA WALNUT CREEK
Project Site Plan
figure 1
Remaining residential parcels (without site plans) as part of Phase 1 development include the
following:
Site Al:
228 dwelling units
Site A3:
190 dwelling units
Site C:
405 dwelling units
In all, there would be 1,505 residential units planned for Phase 1 residential development within
the planned Dublin Transit Center.
Residential Trip Generation
Based on previous analyses conducted for the Dublin Transit Center, residential trip generation
rates were based on the Institute of Transportation Engineers (ITE) research on standard
apartment (multi-family) uses. These peak hour rates were further discounted by 25 percent due
to their proximity to the East Dublin BART Station. ~ With new project site plans for areas A2,
B 1, and B2, a comparison was made of ITE residential trip rates specific to the proposed uses
including condominium, townhome, and apartment uses. The trip rate comparison was done to
ensure the most conservative residential trip rate is being used. Based on the latest ITE research,
the AM and PM peak hour apartment rate would be the most conservative, consistent with
previous analyses conducted for the Transit Center. For the AM peak hour, a rate of 0.38 trips
per unit and during the PM peak hour a rate of 0.47 trips per unit was used (includes 25 %
discount for proximity to BART).
AM and PM peak hour trip generation by development site for the proposed residential
development has been shown in Table 1. As calculated, residential Phase 1 development within
the Dublin Transit Center would generate 573 AM peak hour trips and 707 PM peak hour trips.
It is noted that this peak hour trip generation is consistent with previous analyses conducted for
the Dublin Transit Center based on a residential project description of 1,500 units. That study
indicated 570 AM peak hour trips and 705 PM peak hour trips.:
B. Related Development Uses Within the Dublin Transit Center:
In addition to the Phase 1 Avalon Bay residential development, there would be other planned
development within the Dublin Transit Center that would affect traffic flows in the study area.
~City of Dublin, DEIR Dublin Transit Center, City of Dublin File No. PA 00-013, Prepared by
Jerry Haag, Urban Planner, July 2001.
2Omni-Means Engineers & Planners, Consultant's Report: Transportation Impacts for the Proposed
Dublin Transit Center, City of Dublin, Draft Report, April 27, 2001.
Table 1
Phase 1 Avalon Bay Dublin Transit Center
Residential Trip Generation, AM and PM Peak Hour(~>'")
Developments with Site Plans:
Site A2 (112 Units):
AM Peak: 112 x 0.38 trips/unit = 43 (9 in, 34 out)
PM Peak: 112 x 0.47 trips/unit = 53 (36 in, 17 out)
Site B1 (260 Units):
AM Peak: 260 x 0.38 trips/unit = 99 (20 in, 79 out)
PM Peak: 260 x 0.47 trips/unit = 122 (82 in, 40 out)
Site B2 (310 Units):
AM Peak: 310 x 0.38 trips/unit = 118 (24 in, 94 out)
PM Peak: 310 x 0.47 trips/unit = 146 (95 in, 51 out)
Developments without Site Plans:
Site A1 (228 Units):
AM Peak: 228 x 0.38 trips/unit = 87 (17 in, 70 out)
PM Peak: 228 x 0.47 trips/unit = 107 (70 in, 37 out)
Site A3 (190 Units):
AM Peak: 190 x 0.38 trips/unit = 72 (14 in, 58 out)
PM Peak: 190 x 0.47 trips/unit = 89 (58 in, 31 out)
Site C (405 Units):
AM Peak: 405 x 0.38 trips/unit = 154 (31 in, 123 out)
PM Peak: 405 x 0.47 trips/unit = 190 (124 in, 66 out)
Total Residential Project Trips:
AM Peak Hour:
PM Peak Hour:
= 573 (115 in, 448 out)
= 707 (465 in, 242 out)
(1)
(2)
Institute of Transportation Engineers (ITE), Trip Generation., 7th Edition, Apartment
Uses, Peak hour rates reduced by 25 % to account for proximity to East Dublin BART.
Based on previous analyses conducted for the Dublin Transit Center; Jerry Haag, Urban
Planner, DEIR Dublin Transit Center, CiO' of Dublin, Jul3' 2001.
4
This would include additional retail, BART, and office uses which can be summarized as follows:
Retail Development:
54,700 square feet
BART Garage:
1,680 Parking Spaces
Office Development:
2,000,000 square feet
Related peak hour trip generation for both the BART Garage and Office development can be
found in previous analyses conducted for the Dublin Transit Center?
With respect to planned retail trip generation; all retail trip generation would be considered
"ancillary" to residential and office uses within the Dublin Transit Center consistent with
previous transportation studies. The total retail development with the Transit Center could
potentially generate 190 PM peak hour trips (70,000 square feet x 2.71/trips; ITE, Specialty
Retail). This would equate to 95 customers during the peak hour. The 1,505 residential units
and 2,000,000 square feet of office in Transit Center could easily generate this many customers
to support the retail development. For this reason, all peak hour retail trips are assumed to be
internal to the Transit Center.
C. Future Traffic Conditions At Adjacent External Conditions:
Dublin Boulevard External Access
Primary access to the Phase 1 residential development within the Dublin Transit Center would
be to/from Dublin Boulevard. Specifically, the intersections of De Marcus Boulevard/Dublin
Boulevard and Iron Horse Parkway/Dublin Boulevard would provide main access into the
residential areas. In addition, there would be other limited access streets (right-turn in/out only)
from development site A2 and between sites B1 and B2.
To ensure consistency with more recent transportation studies conducted in the study area,
cumulative buildout turning movement volumes were derived for the De Marcus
Boulevard/Dublin Boulevard and Iron Horse Parkway/Dublin Boulevard intersections from a
study performed for the proposed Camp Parks Phase 1 development in the City of Dublin? By
having the most recent AM and PM peak hour buildout turning movement volumes from these
two external intersections, a review of residential assignment trips was conducted. If necessary,
~Omni-Means Engineers and Planners, Consultant's Report: Dublin Transit Center, Ibid ........
4TJKM Transportation ConsUltants, Phase 1 Traffic Study for the Pro¢osed Parks Reserve Forces
Trainin~ Area (RFTA) Development, City of Dublin, Revised Draft, October 17, 2003.
5
small adjustments in the assignment of residential trips were made to ensure the most
conservative peak hour volumes were used at these two, full-access external intersections on
Dublin Boulevard.
D. Project Specific Analysis: Avalon Bay Phase 1 Internal Intersection Operation:
Internal Study Intersections
Based on a meeting with Dublin Engineering staff, the following 12 intersections were evaluated
for cumulative buildout volumes and operation:
1. Dublin Boulevard/Access for Sites Al, A2, and A3
2. Street "A"/Access for Sites Al, A2, and A3
3. De Marcus Boulevard/Access for Sites A2-A3
4. De Marcus Boulevard/Access for Ske B1
5. De Marcus Boulevard/Village Green/Access for Site A3
6. Dublin Boulevard/Access for Sites B1 and B2
7. North-South Access Street B1 and B2/East-West Access Street B1
8. Village Green/Access for Sites B1 and B2
9. Iron Horse Parkway/Access for Site B2
10. Iron Horse Parkway/Village Green/Martinelli Way
11. Iron Horse Parkway/Access for BART Garage
12. Arnold Road/Altamirano Road
Residential Trip DistribUtion
Residential peak hour trip distribution has been based on previous studies conducted for the
Dublin Transit Center and would be as follows:
Hacienda Drive to/from the south: 45 %
Hacienda Drive to/from the north: 3 %
Dublin Boulevard to/from the east: i0 %
Dublin Boulevard to/from the west: 40%
Arnold Drive to/from the north: 2%
Total:
100%
in addition to peak hour residential project trips, other peak hour trips related to planned BART
Garage and Office development have been added to the internal street network based on previous
analyses conducted for the Transit Center.5 It is noted that (with respect to BART and Office
development), only those peak hour volumes that would affect the 11 internal intersections are
SOnmi-Means Engineers and Planners, Consultant's Rel~ort: Dublin Transit Center. Ibid ....
included. The reason for this is that all the office development is located east of Iron Horse
Parkway. In addition, both office and BART patrons will be able to access the Dublin Transit
Center from other roadways located east of the study area (please refer to l::igure 1).
Cumulative AM and PM peak hour intersection volumes with Phase 1 residential development
have been shown in Figure 2.
Internal Intersection Operation
Based on site plans lines provided for residential and roadway development, the study
intersections' lanes have been identified and LOS have been calculated (shown in Table 2).
Traffic signal control is recommended at intersections 4, 9, 10, and 11. Signal controls will
accommodate traffic flows and prevent excessive queuing at these higher volume internal
intersections. A brief summary of each study intersection's operation follows:
1. Dublin Boulevard/Access for Sites Al, A2, and A3 (Street "A"):
The north/south access street from sites Al, A2, and A3 (Street A) would be a two-lane
street with limited access to/from Dublin Boulevard (right tums only inbound/outbound).
At Dublin Boulevard northbound Street "A" would be stop-sign controlled. Projected
intersection LOS would be D (27.1 seconds of delay) during the AM peak hour and LOS
C (21.2 seconds of delay) during the PM peak hour.
2. Street "A"/Access for Sites Al, A2, and A3 (one-way westbound):
The access for sites A 1,' A2, and A3 would extend between De Marcus Boulevard and
Street "A". In this section, the street would be one-way in the westbound direction.
West of Street "A", there would be a driveway extension into Site Al. The one-way
westbound access street to sites Al, A2, and A3 would be stop-sign controlled at Street
"A" as would the opposing driveway in site Al. Projected intersection LOS would be
A (9.0 seconds of delay) during the AM peak hour and LOS A (9.3 seconds of delay)
during the PM peak hour.
3. De Marcus Boulevard/Access for Sites A2-A3:
The east-west access street between De Marcus Boulevard and Street A would be one-way
in the westbound direction. The intersection at De Marcus Drive would be limited to
southbound right-turns only. Since there are no conflicting movements, intersection delay
is projected to be LOS A with a delay of less than 5 seconds.
7
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Table 2
AM and PM Peak Hour Operation of Internal Phase 1 Development Intersections(''(z)'(3)
Intersection / Control
Unsignalized
Intersections
Signalized
Intersections
AM PM AM PM
LOS LOS LOS LOS
1. Dublin Boulevard/Access for Sites Al, A2, and A3
one-way stop control
2. Street "A"/Access for Sites Al, A2, and A3 two-way stop control
3. De Marcus Boulevard/Access for Sites A2-A3 no control
4. De Marcus Boulevard/Access for Site B1 one-way stop control
5. De Marcus Boulevard/Village Green/Access for Site A3
all-way-stop-comrol
6. Dublin Boulevard/Access for Sites B1 and B2
one-way stop control
7. N-S Access St. B1 and B2/E-W Access St. B1
one-way stop control
8. Village Green/Access for Sites B1 and B2 one-way stop control
9. Iron Horse Parkway/Access for Site B2 one-way stop control
10. Iron Horse Parkway/Village Green/Martinelli Way
signal control
i 1. Iron Horse Parkway/Access for BART Garage signal control
12. Arnold Road/Altamirano Rd. signal control
D27.1 C21.2
A 9.0 A 9.3
A5.0 A5.0
A 9.5 A 9.9
A8.9 A8.6
C 23.8 C 22.2
A 8.9 A 9.6
A8.4 A9.0
D30.4 C 19.5
A 0.59 B O.62
A 0.34 A 0.44
A 0.37 A 0.46
(1)
(2)
(3)
Transportation Research Board, 2000 Highway Capacity Manual, Chapter 17, Unsignalized Intersections.
Contra Costa Transportation Authority (CCTA) methodology for signalized intersections.
Intersection LOS for unsignalized locations represents average vehicle delay in seconds for stop-sign
controlled minor street traffic. Intersection LOS for signalized intersection represents a volume/capacity
(v/c) ratio.
9
4. De Marcus Boulevard/Access for Site BI:
The east-west access street providing access to site B1 would be a two-way, two-lane
roadway. A raised median on De Marcus Boulevard would allow southbound left-turns
(inbound) and westbound right-turns (outbound). For adequate storage capacit3, in the
median, the southbound left-turn storage lane on De Marcus Boulevard should have 100
feet of storage length with a 90 foot transition (based on 63 left-turning peak hour
vehicles). There would be no outbound (westbound) left-turn movements from the B1
access street onto De Marcus Boulevard. At De Marcus Boulevard the westbound B1
access street would be stop-sign controlled. Projected intersection LOS would be A (9.5
seconds of delay) during the AM peak hour and LOS A (9.9 seconds of delay) during the
PM peak hour.
5. De Marcus Boulevard/Village Green/Access for Site A3:
At this intersection, De Marcus Boulevard would be wide, two-lane roadway with a
raised median and parking on both sides. The east-west streets of Village Green and A3
access would be two-lane streets with a raised median. All four approaches would consist
of a shared right, through, and left-turn lane. The north-south AM and PM peak hour
volumes on De Marcus Boulevard could marginally be considered for signal control.
However, with refined peak hour volume projections at this intersection an all-way-stop
control would be adequate. Projected intersection LOS would be A (8.9 seconds of
delay) during the AM peak hour and LOS A (8.6 seconds of delay) during the PM peak
hour with ail-way-stop-control.
6. Dublin Boulevard/Access for Sites B1 and B2:
The access street for sites B1 and B2 would be one-way northbound at its intersection at
Dublin Boulevard and be limited to right-turns-only outbound. Projected intersection
LOS would be C (23.8 seconcts of delay) during the AM peak hour and LOS C (22.2
seconds of delay) during the PM peak hour.
7. North-South Access Street B1 and B2/East-West Access Street Bi:
Both the north-south B1/B2 and east-west B1 access streets would have two travel lanes.
At the north-south B1/B2 access street, eastbound B1 access street would be stop-sign
controlled. Projected intersection LOS would be A (8.9 seconds of delay) during the AM
peak hour and LOS A (9.6 seconds of delay) during the PM peak hour.
8. Village Green/Access for Sires B1 and B2:
At this intersection, Village Green would be one-way westbound with one travel lane and
parking on its north side. The B l/B2 access street would have one lane in each direction
and be stop-sign controlled for the right-turn-only onto Village Green. Projected
10
intersection LOS would be A (8.4 seconds of delay) during the AM peak hour and LOS
A (9.0 seconds of delay) during the PM peak hour.
9. Iron Horse Parkway/Access for Site B2:
At this intersection, Iron Horse Parkway would have three travel lanes; one southbound
lane and two northbound lanes. The access driveway into site's B1 retail garage would
have one lane inbound and one lane outbound. The eastbound (outbound) lane from the
B1 retail garage would be stop-sign controlled. Northbound left-turn movements into the
parking garage from Iron Horse Parkway would not have a separate left-turn storage lane.
However, the amount of northbound left-turn movements would not be significant enough
to affect through-traffic on Iron Horse Parkway. Projected intersection LOS would be
D (30.4 seconds of delay) during the AM peak hour and LOS C (19.5 seconds of delay)
during the PM peak hour.
10. Iron Horse Parkway/Village Green/Martinelli Way:
This would be a standard, four-leg intersection with Iron Horse Parkway comprising the
north-south legs and Village Green and Martinelli Way comprising the west and east legs,
respectively. Ail four approaches would have a shared left, through, right-turn lane with
the exception of westbound Martinelli Way. At this approach, there would be a separate
free-flow right-turn lane northbound onto Iron Horse Parkway. Consistent with the
Transit Center traffic study, this location was analyzed as a signalized intersection and
would operate at LOS A (0.59 v/c ratio) during the AM peak hour and LOS B (0.62 v/c
ratio) during the PM peak hour.
11. Iron Horse Parkway/Access for BART Garage:
At this three-way intersection, Iron Horse Parkway would have two southbound lanes and
one northbound lane. The BART garage access would have two inbound lanes and one
outbound lane. The third leg of Main Street would provide one northbound lane and one
southbound lane (in a southwest direction). Outbound (northbound) left-turn movements
from the BART garage onto Main Street (west) would be prohibited. This location was
analyzed as a signalized intersection and would operate at LOS A (0.34 v/c ratio) during
the AM peak hour and LOS A (0.44 v/c ratio) during the PM peak hour.
12. Arnold Road/Altamirano Road:
At this three-way intersection, Arnold Road would form the north leg, Altamirano Road
would form the west leg, and the proposed Ikea Store the eastern leg. Southbound
Arnold Road would have two travel lanes (one in each direction) as would Altamirano
Road. This location was analyzed as a signalized intersection and would operate at LOS
A (0.37 v/c ratio) during the AM peak hour and LOS A (0.46 v/c ratio) during the PM
peak hour.
11
E. Access, Circulation, and Parking:
The following section specifically outlines the access, circulation, and parking characteristics with
respect to the three residential areas with site plans (sites A2, BI, and B2). Where necessary,
recommendations have been made to improve vehicle circulation and parking. A detailed
discussion of each site follows:
Site A2
The proposed 160 on site garage spaces would not meet the standard of 1.5 spaces per unit or
168 total spaces (112 units @ 1.5/unit). Presumably, the 5 curb spaces along the site's private
access road frontage could be counted as on site, reducing the deficit to only 3 spaces.
The on-site garage design would include a total of 70 tandem' spaces. Since maneuvering in/out
of these spaces can be difficult, we assume that the tandem spaces would be reserved for the
larger apartment units.
As noted in the discussion of Site B2, about 15 % of the total parking or 25 spaces would be
needed to serve residential visitors. With a limited access parking garage, how will visitors enter
and exit the facility?
We recommend that the garage entrance/exit controls be designed to readily allow
visitors to gain access to and from the garage.
The private drive separating sites A2 and A3 would be a satisfactory design for passenger cars.
However, it appears that even single unit trucks would be unable to negotiate the roadway's
curved alignment and would likely not be able to access the designated loading zone at the west
end of this roadway.
We recommend that the De Marcus Boulevard curb frontage have a truck loading
zone and that the private roadway along the south side of the site be designed to
accommodate single unit truck access.
Site Bi:
The 20 foot wide roadway section separating the condominiums from the townhouses is too
narrow to allow reasonable access in/out of the townhouse tandem garages. The 20 foot width
would allow two-way traffic flows, but could not accommodate a temporary parking lane when
townhouse residents have to maneuver one or both cars out of the garages. It is also noted that
the 20 foot width would require eastbound vehicles to travel in the westbound lane in order to
achieve the necessary turning path into these narrow garages. The 28 foot wide section would
better accommodate these parking and vehicle maneuvering functions. The 28 foot width would
12
allow a temporary parking lane along the garage frontages. This width would also allow a
proper turning path into the garages by eastbound vehicles.
We recommend that this roadway be at least 28 feet in width to accommodate vehicle
paths and temporary parking.
The site plan suggests that two garage ramps lead to/from separate levels of parking for the
condominium units.
We recommend that both ramps and parking levels have some guest parking so
guests do not encounter a confusing parking pattern.
We would also recommend that the on-street parking along Village Green be signed
for short-term use by residential visitors.
Truck loading zones are shown along the frontages on Village Green and the one-way
northbound roadway separating sites B1 and B2 (a small loading zone is also shown along the
site's De Marcus Boulevard frontage). Our turning templates indicate that access to these zones
via Village Green would be constrained for single unit trucks and not possible for tractor/trailer
trucks.
We recommend that the internal roadways be reviewed to ensure adequate turning
paths for single unit trucks. We also recommend that a truck loading zone along the
site's De Marcus Boulevard frontage be designed to accommodate larger
tractor/trailer trucks.
Site B2:
The on-site parking would not meet the needs of residential guests and retail customers. Of the
residential units' 465 spaces total parking demand (310 units @ 1.5 spaces/unit), about 15 % or
70 spaces should be allocated for guest parking.~ If half of the retail customers represent local
Transit Center residents the retail would still need about 26 spaces (15,300 sq.ft, retail @ 1
space/300 sq.ft, x 50%). The 96 space demand would exceed the 47 garage spaces, which are
designated for residential guests and retail customers. It is noted that retail parking demand
would occur even though it is expected that the retail area would generate minimal peak hour
trips.
We would recommend that consideration be given to designing the garage such that
a portion of the upper level parking is available for residential visitors, reserving the
first level's 47 spaces for retail customers and very short-term residential visitors.
This concept would probably require that the gated control be modified to allow
residential visitors access to at least a portion of the upper level of the garage.
~The Eno Foundation, (Robert A. Weant and Herbert S. Levinson), Parking, 1990.
13
The retail customers and residential guests could use the on street parking along Iron Horse
parkway and Village Green. It appears that about 30 spaces would be along these street
frontages (18 spaces along the west side of Iron Horse Parkway and 12 spaces in the northeast
section of Village Green). However, even if all of these spaces were available for customers and
guests, the combined total of 77 spaces (47 garage spaces and 30 on street spaces) would not
meet the 96 space demand calculated above.
We would recommend that the on street spaces be time limited (with potentially 2
hour limits) to ensure that these spaces are, in fact, available for customers and
guests.
The garage access serving residents should operate satisfactorily. It is assumed that the peak
hour in/out flows (about 100 out during the AM peak and 100 in during the PM peak) would
pass through a control point with the likely control a coded card reader. Based on standard
parking control service rates and queuing analyses, the inbound and outbound flows would have
a maximum (95 % probability) queue of 2-3 vehicles. A 2-3 vehicle queue for outbound traffic
would occur within the residential portion of the garage and would not significantly affect overall
circulation. A 2-3 vehicle queue for inbound flows could extend back into the garage's internal
circulation, dependent on where the gate is located. It is also noted that the garage entrance on
Iron Horse Parkway would be near a planned mid-block crosswalk. There would be a potential
for conflicts between the driveway traffic and pedestrian activity.
We would recommend that the resident garage access be designed (with controls at
least 75 feet in from the first garage level) so that inbound vehicle queues do not
extend back into the public circulation area of the garage. It is also recommended
that the garage entrance on Iron Horse Parkway be located north of the planned
mid-block crosswalk.
The proposed 8.5 foot x 18.0 foot parking stalls would be satisfactory for the residential and
residential visitor parking. Parking design guidelines recommend 8.75-9.0 foot stall widths for
higher turnover parking associated with retail uses. To the extent that retail customers park in
the garage, the 8.5 foot wide space would be slightly below standard. However, as noted in the
above comment, the garage spaces would not meet the demand of the residential visitors and
retail customers, and it is not clear how many retail customers would actually park in the garage.
We would recommend that the design of the first floor garage spaces allow for
slightly greater widths (8.75-9,0 feet) for retail customer and very short-term
residential visitor spaces.
As noted for Site Bi, truck loading could be somewhat problematic via Village Green and the
private drive separating sites B1 and B2. The retail spaces would have more frequent truck
deliveries and could have deliveries by larger trucks.
14
We recommend that a segment of the site's frontage along Iron Horse Parkway be
'time designated" for truck loading (possibly between 7:00 and 10:00 AM). As
noted above, we also recommend that the internal roadways be reviewed to ensure
adequate turning paths for single unit trucks.
F. Interim Conditions Without BART Garage:
Consideration has also been given to circulation issues during an interim phase of the Transit
Center development. Specifically, this phase would involve completion of the residential
developments on sites A2, B 1 and B2, but retention of the BART surface parking lots (prior to
the planned BART parking garage). The circulation issues reflect access to/from Site A2 and
access to/from sites B1 and B2 and the BART parking lot (Site C) with only the north half of
Village Green completed.
Interim Access for Site A2:
It appears that the east-west access road serving Site A2 will be almost entirely on the BART
parking lot parcel. Construction of this roadway as designed would eliminate the entire northerly
parking aisle in the existing BART parking lot. Thus, the interim access for Site A2 will require
temporary modifications in the site access and the BART lot.
Site A2 can be developed with its garage access to/from the north-south Street "A" along the
west side of the site. This access (via Street "A") could serve inbound access from the west,
outbound access to the west (via a u-turn at Dublin/De Marcus) with limited distance for weaving
and outbound access to the east. However, inbound access from the east would be more
problematic, requiring a u-turn maneuver at the Dublin/Scarlett intersection to the west.
A temporary access should be provided between the BART parking lot and Street A.
We recommend that Street "A" be extended to the south edge of Site A2 and the
BART parking lot be modified to allow access between the lot and the end of Street
A. It appears that the removal of three spaces along the north BART parking lot
could accommodate a two-way access to/from the end of Street A. This access
should be signed within the BART lot as APARTMENT USE ONLY/NO BART
TRAFFIC. It would not be appropriate for the BART patrons to use this
connection to gain access to/from Dublin Boulevard.
Interim Access for Sites BI, B2 and C Via Village Green:
With development of sites B 1 and B2 and the northerly half of the Village Green roadway, access
in/out of the various sites would be altered.
15
Sites B1 and B2 would continue to have full access, even though Village Green would only
include the westbound section. Both of these parcels would have adequate access to/from the
east and west via full access intersections on De Marcus Boulevard and Iron Horse Parkway.
The one-way westbound section of Village Green would serve some function in terms of access
for residential guest and retail customer parking, but would not be imperative in terms of the
primary access needs of sites B 1 and B2.
The BART surface lot (Site C) would have adequate access to/from the west via a full access
intersection on De Marcus Boulevard. Access to/from the east would be somewhat 1/.mired due
to a limited access (right-turns in/out) on Iron Horse Parkway. However, the BART lot could
gain full access to Iron Horse Parkway via the east connection of Village Green.
It is recommended that the BART lot have access to/from Iron Horse Parkway via
the east end of Village Green (the existing BART right-turn only driveway on Iron
Horse Parkway would be closed). The east end of Village Green should have an
interim design, which requires outbound BART traffic to only turn right and exit
onto Iron Horse Parkway. The BART trips would not be allowed to travel west on
the one-way section of Village Green.
G. Intersection Control Recommendations:
The twelve (12) internal project study intersections have been evaluated for appropriate vehicle
controls. Based on previous analyses and intersection LOS calculations, eight (8) of the
intersections would operate acceptably with minor-street stop control (or no control) and these
include the following (see intersection LOS calculation sheets--attached)'
We recommend minor-street stop control at the following intersections:
1. Dublin Boulevard/Access for Sites Al, A2, and A3
~ Street A ,Access for Sites A1 A2 and A3
3. De Marcus Boulevard/Access for Sites A2-A3 (no control applicable)
4. De Marcus Boulevard/Access for Site B1
6. Dublin Boulevard/Access for Sites B1 and B2
7. N-S Access St. B1 and B2/E-W Access St. B1
8. Village Green/Access for Sites B1 and B2
9. Ir0n Horse Parkway/Access for Site B2
At the De Marcus Boulevard/Access for Site BI intersection, we would also
recommend the southbound left-turn storage lane on De Marcus Boulevard to have
100 feet of storage length with a 90 foot transition (based on 63 left-turning peak
hour vehicles). This would allow for adequate southbound storage within the median
on De Marcus Boulevard for southbound left-turning vehicles at this intersection.
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The De Marcus Boulevard/Village Green/Access for Site A3 intersection was projected for
signalization based on previous analyses conducted for the Transit Center. However, with
refined AM and PM peak hour projections (based on more detailed site plans), this intersection
would only marginally be considered for signal control. Instead, the City should monitor
volumes at this intersection for excessive vehicle delay and/or queuing but allow unsignalized
control.
We recommend all-way-stop-control at the following intersection:
5. De Marcus Boulevard/Village Green/Access for Site A3
The remaining three (3) internal study intersections would operate at acceptable levels with signal
control consistent with previous analyses for the Transit Center and intersection LOS calculations.
We recommended signal control at the following intersections to accommodate traffic
flows with single lane approach streets and to prevent excessive vehicle queuing at
these higher volume internal intersections:
10. Iron Horse Parkway/Village Green/Martinelli Way
(Related to development of Sites Bi, B2, Site C, BART, and Office)
11. Iron Horse Parkway/Access for BART Garage
(Related to development of BART)
12. Arnold Road/Altamirano Rd.
(Related to development of BART, Office, and Ikea)
We trust that this report responds to your needs. Please call us with questions or comments.
S inc/c,r~ty,
George V%dN'ickelson, P.E.
Branch Manager
Attachments
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