HomeMy WebLinkAboutBOARDWALK CROSSING FILING 2 MINOR SUBDIVISION - 76 93 - SUBMITTAL DOCUMENTS - ROUND 1 - TRAFFIC STUDY. V.':.
for this property. It is concluded that the auxiliary lane
required for the proposed right-in/right-out access to College
Avenue meets sound engineering design criteria for the posted speed
on College Avenue and the expected turning speed at the access.
the north will shorten the right -turn auxiliary that will be
associated with this access.
According to available aerial photography and site plans, a
taper for an auxiliary lane begins approximately 80 feet south of
the centerline of Boardwalk Drive. The photography and site plan
show a taper length of 90 feet. This portion is built. The
distance from the end of the taper to the beginning of a 40 foot
radius arc for this proposed access is 250 feet. Therefore, the
available lane and taper will be 340 feet. According to the "State
Highway Access Code" (SHAG), the auxiliary lane at this location
should be 295 feet (40 mph) with a 15:1 taper (desirable - 1801).
Based upon traffic studies for this property, the right -turn
movement would be 24 and 38 vehicles in the respective peak hours,
resulting in a design hourly volume (DHV) of 31. According to the
SHAG, this DHV would require summing the auxiliary lane and the
taper, resulting in a total length of 475 feet.
It is pertinent to understand how the deceleration lane length
(295') from the SHAC was determined. This length involves two
calculations. The first involves the perception -reaction time
needed to begin the deceleration process. The second is the actual
deceleration from the posted speed (40 mph) to the turning speed.
In this case, it is 15 mph for a 40 foot radius curb return. At
40 mph, the perception -reaction time is half (1471) of the length
of the deceleration lane. The perception -reaction time, in this
case, is the amount of time necessary for the driver to realize
that he wants to make the turn and then begin to apply the brakes.
The above perception -reaction length assumes a time of 2.5 seconds.
This length of time was determined through research pertaining to
stopping sight distance. This pertains to an unexpected
occurrence. In the case of entering a commercial area, the
occurrence is expected. Research indicates that the 85th
percentile driver reaction time for an expected occurrence is 66%
of the unexpected occurrence. Therefore, it is reasonable to use
less time (1.7 seconds). This reduces the length covered to 100
feet rather than 147 feet. This results in a length of
deceleration lane of 248 feet (148' + 1001). This may be rounded
to 250 feet for design purposes. Based upon the above information,
it is concluded that the available length of right -turn auxiliary
lane (2501) is sufficient for a vehicle to decelerate from 40 mph
to 15 mph without negatively impacting the through traffic on
College Avenue.
The existing taper angle, which results in a 90 foot taper
length is less than that required by the SHAC. Ninety feet is
generally accepted as a reasonable length of taper in urban areas,
but will likely require a variance to the SHAC.
Conclusion.
It is concluded that the proposed REI retail building is in
conformance with trip generation used in the previous traffic study
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Date:
Subject:
MEMORANDUM
Eldon Ward, Cityscape
Fort Collins Staff
Matt Delich -WE-1)
November 1, 1993
REI traffic study (File: 9382MEM1)
This memorandum documents various traffic analyses
related to the REI retail building, located in the southwest
quadrant of the College/Boardwalk intersection. The "Traffic
Impact and Accessibility Analysis, Garth Commercial Plaza,"
December 1982, by Leigh, Scott, & Cleary, Inc. was reviewed
as part of this analysis. Specifically, this memorandum
addresses: (1) compliance of the proposed use to the uses
assumed in the previous study, and (2) compliance with the
"South College Avenue Access Control Plan."
Trip Generation
The REI retail building will house a recreational
equipment store. This is considered a specialty retail use.
Institute of Transportation Engineers' research indicates that
specialty retail uses have a significantly lower trip
generation rate compared to shopping center type retail uses.
The rate can be as much as half the shopping center rate. The
REI building area will be 30,600 square feet at full
development. This is more than the 16,500 square feet of
retail use in the cited traffic study. However, the fast food
restaurant used in the cited traffic study was twice the size
of the existing KFC restaurant. Assuming all other uses from
the cited traffic study remain the same, the trips generated
from the additional retail space are in general conformance
with the overall trip generation.
Access to South College Avenue
I have been requested to comment on the access to the REI
site as it relates to the "South College Avenue Access Control
Plan." The REI Site Plan shows a right-in/right-out access
located approximately 470 feet south of the centerline of
Boardwalk Drive. The "South College Avenue Access Control
Plan" shows this right-in/right-out access 810 feet north of
the centerline of Troutman Parkway. This would place the
allowed access 650 feet south of the centerline of Boardwalk
Drive. The location of the proposed access is approximately
180 feet north of the allowed location. This relocation to
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MEMORANDUM
To: Kerrie Ashbeck, Fort Collins Development Engineer
Teresa Jones, CDOT
Eldon Ward, Cityscape
Steve Olt, Fort Collins Planning Department
Rick Ensdorff, Fort Collins Transportation Division
From: Matt Delich
Date: January 27, 1994
Subject: REI traffic study proposal (File: 9382MEM2)
The purpose of this memorandum is to state the proposed
auxiliary lane configuration for the Boardwalk Crossing
access. This access is located 465+ feet south of Boardwalk
(centerline to centerline). This lane will have the following
elements:
Radius - 40 feet
Length of full width lane - 250 feet
Taper - 90 feet
I have attached my November 1, 1993 memorandum in which I
discussed the auxiliary lane design considerations.