Shadowridge P3/FP-SY 881031ROADWAY SIZING STUDY
FOR
COPPELL ROAD
Prepared For:
Mr. Steve Stolte
Fox & Jacobs
Prepared By:f~L...i
OCT
DeShazo, Starek & Tang, Inc.
330 Union Station
Dallas, Texas 75202
(214) 748-6740
October 31, 1988
TABLE OF CONTENTS
Page
· 1
PURPOSE .................
" 1
STUDY AREA .................
5
AREA ROADWAY NETWORK ..............
· 7
TRAFFIC PROJECTIONS .............
7
TRIP GENERATION ...............
.10
TRAFFIC DISTRIBUTION .............
.15
ROADWAY SIZING ...............
.18
CONCLUSION .................
I
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LIST OF FIGURES
Fi gu re_
1
3
4
6
7
8
9
10
page
EXISTING ROADWAY NETWORK ...... . .... 2
EXISTING ZONING ............. 3
CITY OF COPPELL THOROUGHFARE PLAN ....... 4
FUTURE LAND USE PLAN ........... 6
YEAR 2010 DAILY TRAFFIC PROJECTIONS ...... 8
TRAFFIC ORIENTATIONS .......... 11
DAILY TRIP ASSIGNMENT-EXISTING ZONING ..... 12
PEAK HOUR TRIP ASSIGNMENT-EXISTING ZONING . · · 13
DAILY TRIP ASSIGNMENT-FUTURE LAND USE PLAN . · · 14
PEAK HOUR TRIP ASSIGNMENT-FUTURE LAND USE PLAN. · 16
Table
1
2
3
LIST OF TABLES
TRIP GENERATION SUMMARY-EXISTING ZONING ....
TRIP GENERATION SUMMARY-FUTURE LAND USE ....
CITY OF COPPELL STANDARD ROADWAY WIDTHS ....
Page
. 9
.10
.18
iii
Enginee~ · Planners
Union Station · Dallas, Texas ?$202 · 214/748-6740
TECHNICAL MEMORANDUM
TO:
FROM:
DATE:
SUBJECT:
Mr. Steve Stolte
Fox & Jacobs
DeShazo, Starek & Tang, Inc.
October 31, 1988
Roadwa Sizin Stud for Co ell Road; J88308
PURPOSE
The purpose of this memorandum is to evaluate the projected traf-
fic volumes on Coppell Road between Sandy Lake Road and Bethel
Road in Coppell, Texas and determine the appropriate pavement
width for this section of Coppell Road.
STUDY AREA
Figure I illustrates the existing major roadway system of the
City of Coppell. Copp~ll Road is currently a two-lane, undivided
roadway extending from S.H. 121 generally south to Southwestern
Road. The existing land uses along Coppell Road between Sandy
Lake Road and Bethel Road are mainly residential. Single family
homes are located along the east side and a trailer park is
located west of the road. A fire station, a church and general
retail are located along Coppell Road near Bethel Road. Figure 2
depicts the existing zoning for the area expected to use Coppell
Road.
Figure 3 represents the City of Coppell's Future Thoroughfare
Plan. Coppell Road is shown on the Thoroughfare Plan as a four-
lane undivided, minor arterial. The future land use plan
designates this area as primarily single-family with some medium
THWEAT RI::).
SANDY LAKE RD.
SCHOOL RD.
BELT UNE RD.
FIGURE 1
Existing Roadway Network
>-
SANDY LAKE RD
STUDY AREA-
.,'..,~. ,,..,:.,,. 0,.',,
:.',......
":,'..'i::5: 9,'
BETHEL RD
SCHOOL RD
FIGURE 2
Existing Zoning
LEGE N D
~ SF-12 Single Family Land Use
SF-9 Single Family Land U~'
~ 2F-9 Two Family Residential Land Use
~ MF-2 Multi-Family Land ~
R Retail Land Use
C Commercial Land Use
C4U
M6D
C4U
RD.
SANDY LAKE RD.
M6D
BETHEL RD.
P6D
COWBOY DR.
C4U
SCHOOL RD.
M60
P6D BELT UNE RD.
FIGURE 3
City of Copl~ll
Thoroughfare Plan
density uses west of Coppell Road. An elementary school is
planned to be located on the east side of Coppell Road north of
Plantation Road. Figure 4 illustrates the future land uses of
the study area.
AREA ROADWAY NETWORK
The City of Coppell is located northeast of the Dallas/Fort Worth
International (D/FW) Airport. This location presents excellent
access opportunities to n~jor freeways serving both Dallas, Fort
Worth and the mid-cities. Major roadways serving'-Coppell inclu-
de:
I.H. 635 - is currently a four-lane divided, grade separated
freeway in the vicinity of Coppell. I.H. 635 provides
access to north Dallas and other major freeways. I.H. 635
is planned to be upgraded to a six-lane, divided freeway
from the Tarrant County Line to Valley View Lane by the
State Department of Highways and Public Transportation
(SDHPT).
· S.H. 114 - is a four-lane divided freeway extending from the
Tarrant County Line north of the D/FW Airport to I.H. 35E
northwest of downtown Dallas. This gradb-separated facility
provides excellent access to downtown Dallas from the
Coppell area.
· S.H. 121 - is currently a four-lane divided, at-grade road-
way located west of Coppell which provides access to the
north to Lewisville and I.H. 35E and to the south to D/FW
Airport, Fort Worth and the mid-cities. S.H. 12! is planned
to be upgraded by the SDHPT to a four-lane, grade separated
freeway with frontage roads from the Tarrant County Line to
north of Coppell.
· I.H. 35E - is a six-lane, grade-separated freeway located
east of Coppell which provides access to such areas as
Denton to the north and Dallas to the south.
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LAKE RD
BETHEL RD
BETHEL
SCHOOL RD
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FIGURE 4
Future Land
Use Plan
LEGEND
Single Family Land Use
I~ Medium Density Land Usc
Belt Line Road - is a six-lane divided, major arterial
extending from south of S.H. 11A to Denton Tap Road. At
Denton Tap Road, Belt Line Road extends east to form a cir-
cumferential route around Dallas.
Denton Tap Road - extends north from Belt Line Road to
S.H. 121 north of Coppell. This roadway is currently being
improved to a six-lane, divided roadway from Sandy Lake Road
to Belt Line Road.
Sandy Lake Road - is an east-west, major arterial extending
from Coppell Road to east of I.H. 35E. This roadway pro--
rides access to I.H. 35E to the east and S.H. 121 to the
west.
· Freeport Parkway - is a north-south roadway extending from
south of S.H. 114 to the north to Bethel Road. This roadway
is shown on the Thoroughfare Plan as a six-lane divided
roadway from south of I.H. 635 to north of S.H. 121.
TRAFFIC PROJECTIONS
The projected daily traffic volumes on the freeways and major
thoroughfares in the vicinity of Coppell were obtained from the
SDHPT's 20-20-19, year 2010 traffic projections. Figure 5
illustrates the projected daily traffic volumes.
TRIP GENERATION
In order to determine the number of vehicles using Coppell Road,
the number of trips generated hy study area must be calculated-
The trip generatiOn rates utilized in this analysis are those
represented in the Institute of Transportation Engineers ~
Generation Manual--, 1987.
The trips generated hy the existing zoning are shown in Table 1.
The number of dwelling units for the single-family "SF-12" and
"SF-9" land uses were calculated using four units per acre, the
m
~:L? t~E RO.
25,100
I
FIGURE 5
I Year 2010 Daily Traffic Projections
(vehicles per day) ~
I
SOURCE: SDHPT 20-20-19
TRAFFIC ASSIGNMENT
duplex "2F-9" land use was assumed to consist of $ units per acre
and the multi-family "MF-2" land use was calculated at 20 units
per acre. "C" land uses were assumed to consist of retail uses
at 0.5:1 floor-to-area ratio. The "R" land use located in the
southwest quadrant of Sandy Lake Road and Coppell Road is pro-
posed to be rezoned to single-family; therefore single-family
lots at a rate of 4 units per acre were assumed on this tract.
Using existing zoning, the study area will generate approximately
46,430 daily trips, about 2,250 a.m. peak hour trips and approxi-
mately 4,150 p.m. peak hour trips.
TABLE 1
TRIP GENERATION SUFIMARY - EXISTING ZONING
(TRIP-ENDS)
LAND USE
8
Dupl ex 64
Mul ti -Family 58
Retai 1 . 31
TOTAL
The future land use plan was also examined. Trips generated by
the single-family land use were calculated using a rate of four
units per acre. The medium-density land use was assumed to
represent multi-family uses at 20 units per acre. Table 2 sum-
marizes the results,
LAND USE
Si ngl e-Fatal l~
TOTAL
TABLE 2
TRIP GENERATION SUMMARY - FUTURE LAND USES
(TRIP-ENOS)
AREA
453
37
490
AMOUNT
(DWELLIN(
UNITS)
1,812
740
DAILY
15,554
19,98_____~6
A.M. P.M.
PEAK HOUR PEAK HOUR
The area analyzed is expected to generate about 20,000 trips
during a twenty-four hour period, approximately 1,500 trips in
the morning peak hour and about 2,000 trips in the evening peak
hour.
TRAFFIC DISTRIBUTION
Coppell is primarily a residential community with the majority of
its residents commuting outside the city for enk~loyment. Keeping
this in mind, the majority of Coppell's enkoloyed residents leave
Coppell in the morning to business centers elsewhere and return
in the evening.
Based on the projected daily traffic volumes on the freeways and
arterial streets around the City of Coppell, the distribution of
traffic to and from Coppell was determined. Figure 6 depicts the
orientations of the traffic by a percentage of the total expected
to approach Coppell.
Using the orientations shown in Figure 6, the trips generated by
the existing zoning and future land uses in the study area were
distributed to the area roadway network. Figure 7 indicates the
daily volumes expected on Coppell Road and Plantation Road, and
Figure 8 depicts the morning and evening directional peak hour
volumes on these roads using the existing zoning. The trips
expected under future land uses are shown in Figure 9 for daily
C4U
22%
C4U
S/~DY LAKE RD.
I~O
THEL RD.
C4U
22%
P6D
~CHOOL RD.
Jl~7%
M6D
P6D
FIGURE 6
Traffic Orientations
~l129 % Ill~
BELT UNE RD.
2,046
LAKE
STUDY AREA
6
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BETHEL RD
RD
Z
0
Z
BETHEL
SCHOOL RD
FIGURE 7
Daily Trip Assignment-Existing Zoning
12
~ 8'~76
H/109'~
SA]
STUDY AREA
292/255
BETHEL RD
RD
t~ BETHEL
SCHOOL RD
LEGEND
**/** A.M. PEAK HOURI P.M. PEAK HOUR
Peak Hour Trip Assignment-Existing Zoning
~3
SANDY LAKE RD
STUDY AREA ! ~
' I
BETHEL
~j~ SCHOOL RD
FIGURE 9
Daily Trip Assignment-Future Land Us~ Plan
traffic volumes and Figure 10 for the a.m. and p.m. peak hour
volumes on Coppell Road and Plantation Road.
ROADWAY SIZING
Using methodologies descrihed in the HiQhway Capacity Manual,
Special Report 209, 1985 (NCM), the number of lanes required for
Coppell Road can be calculated for a desired level of service.
For this study, a level of service B was assumed to be the design
level of service. A level of service B represents a free-flow
condition with the noticeable presence of other vehicles. The
equation used to calculate the number of lanes is as follows:
N : SF/[cj x (v/c) x fw x fhv x fex fp]
where:
N = number of lanes in one direction
SF = service flow rate in one direction
cj = capacity per lane; 1,800 vphpl
v/c = maximum allowable volume-to-capacity ratio
fw : adjustment factor for lane width and lateral clearance
fhv : adjustment factor for heavy vehicles
fe = adjustment factor for environment
fp = adjustment factor for driver population
For Coppell Road from Sandy Lake Road to ~ethel Road:
SF = Existing Zoning: 833 vph (Figure 8)
Future Land Uses: 588 vph (Figure 10)
cj = 1,800 vphpl
v/c = 0.45; LOS B (Table 7-1, HCM)
fw : 0.97; 11 foot la_nes, No lateral obstructions (Table 7-2, HCM)
fhv = 1.0; residential area, no heavy vehicles expected
fe = 0.80; undivided roadway, suburban arPa (Table 7-16), HCM)
fp = 1.0; commuter (Table 7-11, HCM)
Ol
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SANDY LAKE RD
II
STUDY AREA I
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8/44r0
2/
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t
22
BETHEL RD
----!
BETHEL
SCHOOL RD
LEGEND
A.M. PEAK H()I!R/ P.M. PEAK Id¢)l!R
FIGURE 10
Peak Hour Trip Assignment-Future Land Use Plan
1 ()
Using the factors shown above, Coppell Road will require two
lanes in each direction under existing zoning and one lane in
each direction under the future land use plan. However, this
does not take into account non-local traffic usage. Non-local
traffic is defined as the vehicles which are not generated by the
land uses in the study area.
With the widening of Denton Tap Road to a six-lane divided road-
way and the implementation of Freeport Parkway as a six-lane
divided roadway from south of I.H. 635 to north of S.H. 121,
little or no non-local traffic is expected on Coppell Road
between Sandy Lake Road and Bethel Road. However, the maximum
service flow rate for Coppell Road as a four-lane undivided road-
way has been calculated using the factors previously listed. The
maximum number of vehicles in one direction while maintaining
level of service B has been calculated to be 1,257 'vehicles per
hour. By comparing the projected and maximum traffic volumes on
Coppell Road, it has been determined that a level of service B
will be maintained on Coppell Road as a four-lane, undivided
roadway with a vehicle mix including 34% non-local traffic under
existing zoning conditions and 53% non-local traffic under future
land uses.
Table 3 summarizes the standard pavement widths and rights-of-way
associated with specific street classifications in the City of
Coppell. The right-of-way requirements and associated pavement
widths are desirable goals for the Thoroughfare Plan by providing
flexibility to address future capacity restrictions.
17
TABLE 3
CITY OF COPPELL
STANDARD ROADWAY WIDTHS
ROADWAY
CLASSIFICATION
M6D
C4D
C4U
4U
C2
STREET DESIGN
PAVEMENT
WIDTHS
MINIMUM
MEDIAN WIDTH
Major Arteria'
Mi nor Arterial
Mi nor Arterial
Col lector
Collector
2-33'
2-24'
48'
44'
37'
14'
17'
MINIMUM
R.O .W.
100'
85'
65'
60'
60'
Based on the HCM methodology used in this study, the "4U" roadway
classification represents the appropriate pavement width for
Coppell Road between Sandy Lake Road and Bethel Road. This width
allows for non-local traffic usage without disrupting the neigh-
borhoods along Coppell Road.
CONCLUSION
The objective of this study was to determine the appropriate
pavement width for Copp~ll Road between Sandy Lake Road and
Bethel Road. Using the SDHPT's 20-20-19 traffic projections, the
orientations of the traffic in the vicinity of Coppell Road were
developed. The trips generated by the study area were calculated
using the ITE Tr~ Generation Manual, and assigned to the area
roadway network based on the projected orientations.
The methodologies described in the 1985 Hi hwa Ca acit Manual
were used to determine the number of lanes required for Coppell
Road. From these calculations, it was determined the existing
two-lane Coppell Road would serve the projected traffic volumes
based on future land uses and maintain a level of service B.
However, if the existing zoning is developed, Coppell Road should
be widened to a four-lane undivided collector with 11 foot lanes
("4U" Roadway Classification). It was also determined that over
18
one-third of the traffic under existing zoning, and over one-half
of the trips expected under future land uses along Coppell Road
can be non-local traffic and maintain a level of service B when
Coppell Road is widened to a four-lane, undivided collector.
Coppell Road is located between two major arterials, Freeport
Parkway and Denton Tap Road, on the City of Coppell's
Thoroughfare Plan. Freeport Parkway will parallel Coppell Road
approximately 1,200 feet to the west. Denton Tap Road is east of
Coppell Road on a typical one-mile spacing from Freeport Parkway.
With these access opportunities nearby, little non-local traffic
is expected on Coppell Road. Therefore, Coppell Road will
operate at a level of service B or better as a four-lane, undi-
vided collector under the "4U" roadway classification.
19