Thoroughfare-SY 900655BETHEL ROAD
ROADWAY SIZING
IN COPPELL, TEXAS
Prepared for:
Mr. Craig Knight
Centre Development Co., Inc.
in support of Branch Properties
& Baptist Foundation
Prepared by:
DeShazo, Starek & Tang, Inc.
330 Union Station
Dallas, TX 75202
(214) 748 -6740
J90122
June 22, 1990
NOTE:
Figures 5 -8 are not included in this report. These figures represent
the schematic designs for the alternative alignments discussed in this
report. We will deliver these schematics to you as soon as possible.
TABLE OF CONTENTS
i
Page
Purpose
1
Location
1
Thoroughfare Plan
2
Existing Traffic Volumes
2
Proposed Area Development
3
Analysis /Observations
4
Existing Traffic Volume Analysis
4
Projected Traffic Volume Analysis
6
Alternative Cross - Sections
7
Two -Lane Undivided Roadway
8
Six -Lane Divided Roadway
8
Four -Lane Divided to Coppell Rd
9
Four -Lane Divided to Bethel School Rd
9
Recommendations /Conclusions
10
i
LIST OF FIGURES
Figure
Page
1
Roadway Location
12
2
Adjacent Zoning
13
3
Existing Traffic Volumes
14
4
Projected Traffic Volumes
15
5
Existing Alignment
16
6
Thoroughfare Plan Alignment
17
7
Proposed Alignment #1
18
8
Proposed Alignment #2
19
LIST OF TABLES
Table Page
1 Trip Generation Summary 4
ii
�o DeShazo, Starek & Tang, Inc.
Engineers •Planners
"I Vni,
TECHNICAL MEMORANDUM
To: Mr. Craig Knight
Centre Development Co., Inc. in support of Branch Properties &
Baptist Foundation
From: DeShazo, Starek & Tang, Inc.
Date: June 22, 1990
Subject: Bethel Road Roadway Sizing; J90122
PURPOSE
The purpose of this memorandum is to determine the optimum roadway width for
Bethel Road from Denton Tap Road to Freeport Parkway in Coppell, Texas. The
existing and proposed traffic volumes will be examined to determine the
recommended cross - section for this section of roadway.
LOCATION
The location of Bethel Road from Denton Tap Road to Freeport Parkway is illustrated
in Figure 1. To the east of Denton Tap Road, Bethel Road is a four -lane, divided
facility into a residential neighborhood, where the roadway becomes a two -lane street
with parking. West of Denton Tap Road, Bethel Road is a two -lane facility extending
past S.H. 121 into Grapevine.
Adjacent zoning in the vicinity of Bethel Road between Denton Tap Road and
Freeport Parkway is shown in Figure 2. Old downtown Coppell is located just south
of Coppell Road. Grapevine Springs Park is located just west of the Bethel
330 Union Station
Dallas, Texas 75202 -4802
214/748 -6740 Metro 214/263 -5428
Fax 214/748 -7037
1
Road /Bethel School Road intersection on the south side of Bethel Road. South of
Bethel Road, the majority of the zoning in this area is light industrial. The area north
of Bethel Road is either zoned residential or commercial.
THOROUGHFARE PLAN
The City of Coppell Thoroughfare Plan currently depicts Bethel Road as a six -lane
divided major thoroughfare from S.H. 121 to Denton Tap Road. Barton- Aschman
Associates, Inc. has recently completed the Roadway Functional Classification and
Design Standards for the City of Coppell. The report indicates Bethel Road should
be downsized to a two -lane undivided street from Denton Tap Road to Freeport
Parkway. The Plan Commission revised this recommendation to reserve the right -of-
way for a four -lane undivided roadway. From Freeport Parkway to Royal Lane, the
report indicates Bethel Road should be widened to a four -lane undivided roadway.
From Royal Lane to S.H. 121, Bethel Road is planned to be a six -lane divided major
thoroughfare. This report has been accepted and approved by the City of Coppell
Plan Commission to be adopted into the existing thoroughfare plan. The City Council
is expected to discuss this matter at the city council meeting scheduled for June 26th.
EXISTING TRAFFIC VOLUMES
Existing daily traffic volumes were recorded along Bethel Road from Freeport
Parkway to Denton Tap Road and on Denton Tap Road in the vicinity of Bethel Road.
Standard traffic count machines were placed along the streets on June 7 -8, 1990 to
record the existing traffic volumes in the vicinity of the subject roadway. Morning
and evening peak hour turning movements were also examined at the intersection of
Bethel Road and Denton Tap Road in order to analyze the traffic operations at this
2
intersection. Figure 3 depicts the existing traffic volumes on Bethel Road from
Denton Tap Road to Freeport Parkway and Denton Tap Road south of Bethel Road.
PROPOSED AREA DEVELOPMENT
Centre Development Co., Inc. has planned a 118.9 - acre development on the
southwest quadrant of Denton Tap Road and Bethel Road. This tract is currently
owned by the Baptist Foundation. The development is expected to consist mainly of
commercial, light industrial and office uses. The Baptist Foundation has agreed to
donate the Grapevine Springs Park to the City of Coppell to enhance the beauty and
attractiveness of the historical park and make it accessible to the public. Because the
property is divided by Grapevine Creek, the east and west quadrants of the tract are
expected to be developed with different uses. The east side of the tract, with access
to Denton Tap Road, is expected to be developed as commercial uses. The west side
of the tract is expected to be developed as industrial uses because of the limited access
to major thoroughfares. Industrial uses generally generate less trips than commercial
uses. The proposed uses and the number of trips each use is expected to generate is
summarized in Table 1. The proposed development is expected to generate
approximately 25,410 trips in a twenty -four hour period, with 2,010 of these trips
occurring during the a.m. peak hour and 3,040 trips occurring in the p.m. peak hour.
c3
TABLE 1
TRIP GENERATION SUMMARY
(Trip -Ends)
ANALYSIS /OBSERVATIONS
The existing traffic volumes, and the existing with proposed development traffic
volumes were examined to determine the optimum roadway width for Bethel Road
from Coppell Road to Denton Tap Road and intersection lane configurations of Bethel
Road at Denton Tap Road. In order to take a conservative approach, only the trips
expected to be generated by the planned Centre Development project were used to
estimate the year 2010 projected traffic volumes. Other developments in the vicinity
of Bethel Road were not included.
Existing Traffic Volume Analysis
The Barton- Aschman Roadway Functional Classification and Design Standards were
used to determine the roadway link capacities of the various roadway classifications.
The capacities of the various types of roadways considered for this section of Bethel
4
Amount
AM Peak
PM Peak
Use
(S.F.)
Daily
In
Out
In
Out
Commercial
156,800
15,307
263
112
706
735
Office
447,000
5,484
731
109
130
684
Light Industrial
741,000
4,601
686
94
92
672
City Park
223,700
19
6
6
9
9
TOTAL
1,568,500
25,411
1,686
321
937
2,100
ANALYSIS /OBSERVATIONS
The existing traffic volumes, and the existing with proposed development traffic
volumes were examined to determine the optimum roadway width for Bethel Road
from Coppell Road to Denton Tap Road and intersection lane configurations of Bethel
Road at Denton Tap Road. In order to take a conservative approach, only the trips
expected to be generated by the planned Centre Development project were used to
estimate the year 2010 projected traffic volumes. Other developments in the vicinity
of Bethel Road were not included.
Existing Traffic Volume Analysis
The Barton- Aschman Roadway Functional Classification and Design Standards were
used to determine the roadway link capacities of the various roadway classifications.
The capacities of the various types of roadways considered for this section of Bethel
4
Road are listed below:
o Two -lane Undivided -
o Four -lane Undivided -
o Four -lane Divided -
o Six -lane Divided -
0 - 10,000 vehicles per day
10,000 - 20,000 vehicles per day
20,000 - 25,000 vehicles per day
25,000 - 35,000 vehicles per day
By comparing the existing daily traffic volumes shown on Figure 3 to the roadway
capacities shown above, it can be seen that Bethel Road currently operates at 36%
capacity as a two -lane undivided roadway between Denton Tap Road and Coppell
Road. West of Coppell Road, Bethel Road currently operates at 66% capacity.
The unsignalized intersection of Bethel Road and Denton Tap Road was also analyzed
to determine the operation of the intersection during the morning and evening peak
hours. The intersection currently operates at a level of service "F" during both the
morning and evening peak hours. This represents a failing condition. Because of this
condition, a signal warrant analysis was conducted to determine if the intersection
warrants signalization. The intersection currently meets the following warrants:
o Warrant 2, Interruption of Continuous Traffic,
o Warrant 7, Systems Warrant,
o Warrant 9, Four Hour Volumes,
o Warrant 11, Peak Hour Warrant and
o Warrant 12, Warrant Volumes for Traffic Actuated Signals.
The intersection should be signalized as soon as possible to accommodate the existing
traffic volumes, regardless of the ultimate cross - section of Bethel Road. The capacity
analyses and signal warrant analysis are located in the appendix of this memorandum.
I
Proiected Traffic Volume Analvsis
The projected traffic volumes from the expected land uses on the southwest quadrant
of Bethel Road and Denton Tap Road were added to the existing traffic volumes to
analyze the anticipated traffic projections on Bethel Road from Coppell Road to
Denton Tap Road. These traffic projections do not take into account any other
increases in traffic from other future planned developments in Coppell. Figure 4
shows the traffic projections for the daily traffic volumes and the a.m. and p.m. peak
hour turning movements at the intersection of Bethel Road and Denton Tap Road.
Bethel Road is expected to carry approximately 13,200 vehicles per day between
Denton Tap Road and Coppell Road. Between Coppell Road and Freeport Parkway,
Bethel Road is expected to carry approximately 10,500 vehicles per day. Assuming
a design year 2010, the expected yearly growth rate for Bethel Road between Denton
Tap Road and Coppell Road is about 6.7°x6 using the existing with development traffic
projections.
Based on the daily traffic volumes, Bethel Road will operate at 132% capacity between
Denton Tap Road and Coppell Road as a two -lane undivided facility. This indicates
that the expected daily traffic volumes exceed the capacity of a two -lane undivided
roadway. The minimum recommended cross - section for Bethel Road from Denton
Tap Road to Coppell Road is a four -lane undivided roadway. A four -lane undivided
roadway will operate at 66% capacity with the projected traffic volumes expected on
this section of Bethel Road.
Between Coppell Road and Freeport Parkway, Bethel Road is expected to operate at
105% capacity as a two -lane, undivided roadway. The minimum recommended cross-
C.
section for this portion of Bethel Road is a four -lane undivided roadway, which is
expected to operate at 52% capacity.
The intersection of Bethel Road and Denton Tap Road was also examined to
determine the impact of the projected traffic volumes on the intersection. The
intersection was assumed to be signalized in the future. The intersection is expected
to operate at a level of service E in the evening peak hour with Bethel Road operating
as a two -lane undivided facility. If Bethel Road is improved to a four -lane, divided
roadway, the intersection is expected to operate at a level of service C in the evening
peak hour.
The Barton - Aschman Roadway Functional Classification and Design Standards
indicate Bethel Road is expected to carry approximately 6,000 vehicles per day in the
year 2010 based on the TRANPLAN travel forecast model. This indicates a growth
of about 2.6% per year.
ALTERNATIVE CROSS - SECTIONS
9
Five cross - sections were examined to determine the preferred alignment for Bethel
Road. The five cross - sections analyzed were:
1) Two -lane Undivided Roadway (Existing Alignment)
2) Six -lane Divided Roadway (Thoroughfare Plan)
3) Four -lane Divided Roadway, Denton Tap Road - Coppell Road,
Four -lane Undivided Roadway, Coppell Road - Freeport Parkway
4) Four -lane Divided Roadway, Denton Tap Road - Bethel School Road,
Four -lane Undivided Roadway, Bethel School Road - Freeport Parkway.
7
1) Two -Lane 'Undivided Roadway
As illustrated in Figure 5, the existing roadway is a two -lane undivided roadway.
Some of the advantages of using this type of roadway are:
o There is no change in the existing conditions.
o There is no additional right -of -way required.
Some of the di§ advantages of using this cross - section are:
o Bethel Road is expected to operate over - capacity based on
projected traffic volumes.
o Substantial delays will occur for vehicles traveling on Bethel Road
from Denton Tap Road to Freeport Parkway.
o Area development will be limited due to the lack of capacity on Bethel
Road.
2) Six -Lane Divided Roadway
The Thoroughfare Plan for the City of Coppell shows Bethel Road as a six -lane
divided roadway. This alignment is shown in Figure 6. Some advantages of this
cross - section include:
o It provides adequate capacity for the expected year 2010 traffic
volumes.
o This cross - section provides exclusive left -turn lanes at cross - streets.
o The median will provide an area for landscaping.
Some disadvantages of this cross - section are:
o This alternative requires 100 feet of right -of -way.
o The width of the right -of -way will result in the loss of many existing
structures and trees along Bethel Road.
o This cross - section is not required to accommodate the expected year
2010 traffic projections.
3) Four -Lane Divided Roadway to Coppell Road: Four -Lane Undivided Roadway
to Freeport Parkway
Figure 7 depicts this proposed alignment. Some of the advantages of this alignment
are:
This cross - section provides adequate capacity for the development of
existing tract south of Bethel Road between Denton Tap Road and
Coppell Road.
o The alignment of the roadway will provide a landscaped boulevard to
the historical downtown Coppell area.
Some of the disadvantages of this type of roadway are:
o This cross - section requires 80 feet of right -of -way from Bethel School
Road to Coppell Road, fifteen feet more than a four -lane undivided
roadway.
o The density of the tract south of Bethel Road between Denton Tap
Road and Coppell Road is expected to be greater east of Grapevine
Creek. With fewer trips west of Grapevine Creek, a four -lane divided
roadway will be unneccessary.
4) Four-Lane Divided Roadway to Bethel School Road: Four -Lane Undivided
Roadway to Freeport Parkway
The alignment of this section is illustrated in Figure 8. This cross - section will provide
the following advantages:
o It will provide capacity of up to 25,000 vehicles per day on the four -
lane divided section and 20,000 vehicles per day on the four -lane
undivided section.
o This cross- section requires only 65 feet of right -of -way from Bethel
School Road to Coppell Road.
o Many of the existing structures and trees along Bethel Road from
Denton Tap Road to Freeport Parkway may remain if the proposed
right -of -way is reduced through the historical downtown Coppell area.
Some disadvantages of this cross - section are:
o Vehicles turning left to or from Bethel Road west of Bethel School
Road will not be protected by a median from oncoming traffic.
o The wide expanse of unbroken pavement (44 feet) is less aesthetically
pleasing than a four -lane roadway with a median which has only 22
feet of unbroken pavement.
RECOMMENDATIONS /CONCLUSIONS
Bethel Road has been closely examined to determine the optimum roadway width
from Denton Tap Road to Freeport Parkway. The existing traffic volumes were
analyzed to determine the existing level of operation of Bethel Road and the
intersection of Bethel Road and Denton Tap Road. Bethel Road currently operates
at 36% capacity west of Denton Tap Road and 66°x6 capacity west of Coppell Road;
however, the intersection of Bethel Road and Denton Tap Road operates at a level of
service "F" as an unsignalized intersection. This intersection meets the required traffic
signal warrants; therefore, this intersection should be signalized to provide better
traffic flow at the intersection.
Future traffic volumes were estimated based on the expected development on the
southwest quadrant of Bethel Road and Denton Tap Road. These trips were then
added to the existing Bethel Road traffic to determine the estimated year 2010 traffic
projections. It should be noted that although other developments are planned for this
area, they were not included in the analysis in order to take a conservative approach
when examining the expected traffic conditions. Bethel Road should be constructed
to a minimum cross - section of a four -lane undivided roadway based on the year 2010
traffic projections. Bethel Road should be widened to a four -lane divided roadway
at Denton Tap Road to match the existing alignment of Bethel Road east of Denton
Tap Road.
10
A four -lane divided roadway is recommended for Bethel Road from Denton Tap
Road to Bethel School Road, narrowing to a four -lane undivided roadway from Bethel
School Road to Freeport Parkway. This cross - section provides left -turn lanes for
vehicles turning into the adjacent tracts west of Grapevine Creek, therefore providing
a minimum impact of the through traffic on Bethel Road while providing adequate
capacity for the expected year 2010 traffic volumes. This recommended cross - section
also provides an exclusive left -turn lane at Bethel School Road from Bethel Road.
The proposed median provides an excellent opportunity to provide a landscaped
boulevard. This could act as a "gateway" to the Coppell historical downtown district,
to help define the district, while maintaining the majority of the existing structures
and trees in the area by reducing the cross - section to four -lane undivided through the
downtown area.
11
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FIGURE 3
Existing Traffic Volumes
14
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FIGURE 4
Projected Traffic Volumes
15
* * / ** AM Peak /PM Peak
*, * ** 24 -hots' traffic volumes