HomeMy WebLinkAboutTERRY SHORES NORTH - PRELIMINARY SUBDIVISION - COUNTY REFERRAL - 71-88 - SUBMITTAL DOCUMENTS - ROUND 1 - TRAFFIC STUDYTerry Shores North
Traffic Impact Study
Krager ana Hssociases
(A') Boulder Street
Denver: Colorado 80211
(303) 477-6318
TERRY SHORES NORTH SUBDIVISION
TRAFFIC IMPACT STUDY
LARIMER COUNTY, COLORADO
Prepared for:
Junge Reich Magee AIA
4141 Arapahoe Road
Boulder, Colorado 80303
Prepared by:
Krager and Associates
1643 Boulder Street
Denver, Colorado 80211
August, 1988
EXECUTIVE SUMMARY
This traffic impact study addresses the capacity, geometric,
and control requirements at a proposed development known as
Terry Shores North. Terry Shores North is a proposed single
family residential development consisting of 18 dwelling units.
The site is located at the southwest corner of Douglas Road and
Shore Road in Larimer County, Colorado. As a result of this
study, the following is concluded:
The development of Terry Shores North will generate
approximately 180 vehicle trips per day. The PM peak
hour will generate approximately 18 trips.
The addition of Terry Shores North traffic will not
affect the level of service at the intersection of
Douglas Road and Shore Road. The traffic impact to
Douglas Road will be minimal and does not warrant
improvement of Douglas Road.
Traffic within the site will be minimal with no
through traffic using the internal street system. A
rural cross section street would be suitable for this
proposed development.
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I. INTRODUCTION
This traffic impact study addresses the capacity, geometric,
and control requirements at a proposed development known as
Terry Shores North. Terry Shores North is a proposed single
family residential development consisting of 18 dwelling units.
The site is located at the southwest corner of Douglas Road and
Shore Road in Larimer County, Colorado (see Figure 1).
This study addresses the traffic impacts for full development
at the expected opening (1989). Due to the minimal impact of
this site long range traffic projections were not analyzed. The
study involved the following steps:
- Collect physical, traffic and development data.
- Perform trip generation, trip distribution and trip
assignment.
- Determine peak hour traffic volumes.
- Conduct capacity and operational level of service
analyses on key intersections.
- Determine appropriate street designations
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Figure 1
Site Location
II. TRANSPORTATION NETWORK
Existing Network
Terry Shores North will have direct access to Shore Road at
one location, approximately 500 feet south of the Douglas Road
intersection. The intersection of Douglas Road and Shore Road
is an unsignalized intersection with traffic on Douglas Road
having the right of way. Existing PM peak hour traffic counts
for the intersection of Douglas and Shore Roads are shown in
Figure 2. These counts were conducted in August, 1988. Only
PM peak hour counts were taken. Due to the suburban nature of
this area, it is assumed that the AM traffic volumes would be
the reverse of the PM count.
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_ - 73/74
Douglas Rd ,r— 1/3
AM Peak/PM Peak , I
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Figure 2
Existing Traffic
III. TRAFFIC VOLUME PROJECTIONS
Background Traffic
To analyze the impact of a development whem it is completed, it
is important to consider the increases in existing traffic
which are likely to occur. Since the background traffic counts
for this study were recently taken, no increase in traffic was
applied to represent 1989 traffic projections.
Traffic Generation
Standard traffic generation characteristics compiled by the
Institute of Transportation Engineers in their report entitled
"Trip Generation", revised 1985, were applied to the proposed
land use in order to estimate daily and peak hour vehicle
trips. A vehicle trip is defined as a one-way vehicle movement
from a point of origin to a point of destination.
Table 1 illustrates the projected daily and peak hour traffic
volumes generated by Terry Shores North. The estimated daily
trip generation for this project is 180 vehicle trips per day.
The anticipated PM peak hourly volume is 18 vph.
Land Use
Single Family
TABLE 1
Trip Generation
Daily AM Peak Hour PM Peak Hour
Trips In Out Total In Out Total
180 4 10 14 11 7 18
Based on I.T.E. Land Use - Single Family Dwelling
Trip Distribution
The directional distribution of the site -generated traffic
indicates the general way in which access to and from the site
is anticipated. The location of the project with respect to
the urban area and the roadway network are primary factors
dictating the overall directional distribution. The anti-
cipated directional distribution is shown in Figure 3.
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Traffic Assignment
Traffic assignment is how the generated and distributed trips
are expected to be loaded on the roadway network. Figure 4
shows the AM/PM peak hour assignment of the site -generated
traffic. Figure 5 shows the AM/PM peak hour assignment of the
site generated traffic and the background traffic.
L
Douglas Rd ,e- 6 0 %
Ir60%
30%
Figure 3
Trip Distribution
N
Douglas Rd j-2/7
r
N
0
• N
n
AM Peak/PM Peak
Figure 4
Site -Generated Traffic
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-.-73/74
Douglas Rd ,r- 3/ 10
74/73----
2/5 -�
0
CD
AM Peak/PM Peak ••, I
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Figure 5
Total Traffic
IV. ANALYSIS AND FINDINGS
Operational Analysis
Capacity analysis was performed on the intersection of Douglas
and Shore Roads. The Unsignalized Intersection Analysis tech-
nique, as published in "Highway Capacity Manual, Special Report
209," by the Transportation Research Board in 1985, was used.
This technique allows one to determine the overall intersection
level of service based on each traffic movement. Table 2
illustrates the levels of service attained at the intersection
for the AM and PM peak hour traffic projections. The defini-
tions for levels of service are given in Appendix B. The
capacity worksheets are given in Appendix C.
Table 2
Intersection Capacity Analysis Summary
Douglas/Shore
Left Turn from WB Douglas
Right Turn from NB Shore
Left Turn from NB Shore
Level of Service
AM Peak PM Peak
A(717)
A(727)
A(727)
A(709)
A(741)
A(741)
As can be seen from Table 2, the addition of traffic from the
Terry Shores North development will not impact the level of
service at the Douglas/Shore intersection. The intersection
will continue to operate at level of service A, with no delays
expected in traffic. The traffic volumes which will be gene-
rated by the Terry Shores North site are too low to have a
noticeable effect on the surrounding street system. This re-
port recommends that the off -site street improvements be waived
for this development since level of service A is easily
maintained.
Street Designations
The 18 dwelling units in Terry Shores North will be served by
Shores Circle, a proposed private roadway. Shores Circle is
propsed to have cul-de-sacs at either end, with an access to
Shore Road at the approximate mid -point. The developer is
proposing to use a rural cross section for Shores Circle. This
cross section does not provide curb/cutter or sidewalks.
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According the the City of Fort Collins standards, a rural cross
section is appropriate for subdivisions with lot sizes of one
acre or larger and less than 20 dwelling units. The Terry
Shores North subdivision will have fewer than 20 dwelling
units, but the lots are less than one acre, thus requiring a
waiver to construct this street type.
The main traffic concern of rural street cross sections is to
limit the potential conflicts between cars, pedestrians, and
bicycles. This can best be accomplished by restricting the use
of this cross section to only lightly traveled roads. Shores
Circle is estimated to have 180 vehicles per day, all of which
is generated from within the Terry Shores North Subdivision.
Since Shores Circle will be a cul-de-sac, no through traffic
should be present. Traffic with an origin or destination
within Terry Shores North is more likely to be alert to
pedestrians, bicyclists, and other traffic. Due to the low
trip generation and lack of through traffic, a rural cross
section should be acceptable within this subdivision.
Summary
The development of Terry Shores North will not have a signifi-
cant impact on the roadway network in the vicinity of the site.
No change in operating conditions on the local street system is
predicted with the addition of site -generated traffic. Very
good level of service can be maintained with no off -site im-
provements on Douglas Road and the use of a rural cross section
on Shores Circle.
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