SC-Coppell HS-CS 870202Barton.Aschman Associates, Inc.
5485 Belt Line Road, Suite 199, Dallas, Texas 75240
Memorandum To: David Stanfield
Superintendent, Coppell Independent School District
214-991-190u
Copies To:
Jim Boughton - SHWC Architects
Tom Rutledge - Teague, Nall& Perkins
From: Gary Jost
February 2, 1987
Traffic Access Evaluation for the Proposed Coppell High
This memorandum presents the findings and conclusions of a traffic
study conducted for the proposed Coppell High School in Coppell, Texas. The
site for the proposed school is located west of Denton Tap Road, south of
the proposed Parkway Boulevard, and north of Willow Lane. The site location
is illustrated in Figure 1.
The purpose of this study is to evaluate the access requirements to the
'school. As presently proposed, access to the site would be from the Parkway
Boulevard extension, via a connecting driveway, to the northeast corner of
the site. The proposed access configuration is shown in Figure 2. This
study will determine the size requirements of the access driveway as well as
the Parkway Boulevard extensior~
The conditions governing the configuration of the proposed access
roadways are dependent upon the trip generation characteristics of the
school. The primary variable affecting these characteristics are the number
of students enrolled.
The school site is planned to accommodate a maximum of 2500 students.
This enrollment figure is expected to occur in the year 2005. To facilitate
the planning of roadway requirements during the period from school opening
(expected in 1988) to 2005, discussions were held with school district staff
to establish the estimated enrollment for target years between 1988 and
2005. The estimated enrollments are as follows.
FEB
DA,_LAo, TEXAS
Not to Scale
Thweatt Rd.
Ruby
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0
Bethel Rd.
Propoeed
Parkway Blvd.
Extension
I SiTE I
I I
~h~ady
Pla~t~
Lake Rd.
N
Betha Rd,
FIGURE 1
SITE LOCATION
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0
Denton Tap Rd.
om
Barton-Aschman AssOciates, Inc.
Y~=~r
Estimated Enrollment
1988 (school opening) 620
1992 1000
1995 1500
2000 2000
2005 2500
Standard trip generation rates contained in the Institute of Transportation
Engineers (ITE) publication entitled Trip Generation and from Barton-Aschman
files were applied to the expected enrollments to determine the traffic that
will be generated by the school. The trip generation rates used for the
proposed school are given in Table 1. Table 2 indicates the total number of
trips that can be expected during the morning and afternoon peak hours of
school activity.
Table 1
TRIP GENERATION RATES
A.M. Peak Hour
P.M. Peak Hour
and Use In Out In Out
High School
< 2000 students .22 .02 .02 .18
> 2000 students .26 .03 .02 .18
Table 2
TRIP ~NERATION
Design Estimated A.M. Peak Hour P.M. Peak Hour
y~ar Enrol~t In Out In Out
1988 620 137 13 13 112
1992 1000 220 20 20 180
1995 1500 330 30 30 270
2000 2000 520 60 40 360
2005 2500 650 75 50 450
Barton-Aschman Associates, Inc.
The lane requirements for the proposed access roadways were analyzed by.
evaluating the demand, capacity and level of service on the access drives.
The level of service for roadways can range between level of service "A" and
,'P', with level of service "A" representing an optimal and unoongested free-
flowing condition and level of service "P' representing a heavily congested,
forced flow condition. The acceptable design level of service (LOS) for
most large cities if LOS "E~'. However, for this analysis, the design level
of service was assumed to be LOS "C".
The capacities used in this analysis were obtained from the North
Central Texas Council of Governments [NCTCOG) and arethecapacitiesusedin
their regional transportation model. For purposes of this study, the
following capacitieswereused.
Roadway
Classification
LOS "C" Capacity
(veh per hour per lane)
Parkway Boulevard
School driveway
minor arterial 560
collector 440
Based on these roadway lane capacities, the lane requirements for the
access roadways were determined for each year. The results are given in
Table 3.
Table 3
Design
Number of LaDes Required (2-~ay)
Access Driveway Parkway Boulevard
1988 2 2
1992 2 2
1995 2 2
2000 4 2
2005 4 4
BartOn-Aschman Associates, Inc.
The results indicate that two-lane roadways will handle the expected
school generated traffic at an acceptable level of service until, based on
the estimated enrollments, sometime after 1995.
It should be noted that the analysis is based on school generated
traffic only. The lane requirement on Parkway Boulevard will be greatly
affected by other traffic on the roadway after it is completed between
Denton Tap Road and Coppell Road, as proposed. The analysis also does not
include traffic generated bya 6000 seat stadium proposed for the school
site.