ST8201-CS 820907Engineers · Planners
TO:. Honorable Mayor and City Council
Coppell~ Texas
FROM: Urban Systems Consultants~ Inc.
SUBJECT; Traffic Analysis-' Intersection of Beltline Road / Denton Tap Road /
5outhwestern Dr.
Background:
· The intersection is heavily travelled during morning and evening peak traffic
movements.
· Traffic queues are formed on north approach and south approach to a
distance of a half mile during morning and evening peak traffic flow.
· Lack of roadway shoulders contributes to intersection inefficiency and traffic
accidents.
· About 25 to 30% of truck traffic use the intersection during peak periods of
traffic.
· Based on traffic volumes utilizing the intersection, a traffic signal is required
to move traffic through the intersection more safely and effectively.
The four intersection designs proposed by Kyle & Johnson, Inc. Engineers for
Gateway Business Park were reviewed. In the final analysis, similar
alternative proposals were evaluated by USCi.
ALTERNATIVE #1 - ALIGN THE EAST AND WEST APPROACHES TO FORM ONE
INTERSECTION.
Traffic Analysis
Advantacjes
· Intersection design provides for safe and efficient traffic movement.
· Access to adjacent property is adequate.
· Minimum R.O.W. acquisition is necessary to realign east-west approach-
es.
8204 Elmbrook Drive, Suite 250, Dallas, Texas 75247, 214/630-9492
Disadvantages
City of Coppell
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· Intersection is skewed, requires special design for curb radii and median
to accommodate turning movements especially truck traffic.
· Acquisition and disposal of excess land may create problems, legal and
administration.
Land Use Analysis
Acquisition Parcels
Disposition Parcels
Ac. + Parcel Ac. + Parcel
· f~7 'A~ .0~ 'C~
.27 'B' .14 'D I'
1.24 Total .10 'D2'
.51 'E'
.79
Total
Possible Excess Land Disposition
Parcel 'C'-
Parcel 'D '
i-
Parcel 'D2'-
Parcel 'E'-
Sell or deed to P. O. '5'
Abandon R.O.W. and convey back to P. O./~
Abandon R.O.W. and convey back to P. 0.3
Abandon R.O.W. and convey back to P. O.I
Alternate 'D2'/'F' - Retain 'D2' and acquire 'F'. Provide for P. 0.4 driveway
esm't, thru 'D2' and 'F'. Landscape 'D2' and 'F' as focal entry
point into City (mini-park)
Land Use Advantages
· No significant problems~ except drive access from P. 0.4 across 'D2' and 'F'
might need to be retained and acquired.
Land Use Disadvantages
· Land disposition problem w/parcels 'D2' and possibly 'F'.
· Parcels 'D2' and 'F' combined are too small for an effective building lot, when
set backs are included.
· An access esm't, across parcel 'F' will need to be acquired for P. 0.4 access.
City of Coppell
Page 3
Alternative to P. O. 4 Access
· Tie south access drive into parcel 'DI'. Provide new west access to P. 0.4 at
west end of parcel 'Di' with intersection to first N-S westerly cul-de-sac
street.
Cost of Improvements (600 ft. on all approaches)
IR.O.W. Cost
Construction Costs
Signal Construction Cost
Engineering Design Cost
$ 136~00
400,000
65~000
28~000
Total Cost $629,000
ALTERNATIVE tt2 - IREALIGN SOUTHWESTERN DR. WITH BELTLINE ROAD
(EAST)~ REDUCE STANDARD OF DESIGN OF PRESENT SOUTHWESTERN DR. TO
A MINOR ST. OR POSSIBLY ABANDONMENT.
Traffic Analysis
Advantages
· Provide for adequate design to handle future traffic projections.
· Required roadway R,O.W. is obtained from one side only.
· Adequate access is provided to all abutting properties.
· Land between new alignment and present alignment can be platted and
developed.
Disadvantages
· Southwestern Dr. terminus may create problems for development and
platting.
Land Use Analysis
· Double frontage (N-S) exists on parcel 'D'~ which is undesirable from an
aesthetics point of view.
· Two parallel roads 'old' and 'new' Southwestern Dr. are only 150' - 160' apart.
Only one road needed from a traffic "volume" standpoint.
~'~ City of Coppell
' Page
· Median on Denton Tap Rd. prohibits L.T. ! N.B. traffic movement from 'old'
Southwestern Dr. onto Denton Tap Rd.
· Limited parcel 'D' depth (150'- 160') is an awkward depth to divide parcel in
half (N-S) for economical dvlpm't. Zoning ord. probably requires 100' min.
depth of lots.
Cost of Improvements
R.O.W. Cost
Construction Cost
Signal Construction Cost
Engineering Design Cost
$ 255,000
480,000
65,000
30~000
Total Cost $830,000
ALTERNATIVE 1t3 - REALIGN BELTLINE RD. TO EXISTING SOUTHWESTERN
DR. ALLOW FOR AN ACCESS ROADWAY TO SERVE PROPERTY ON THE
SOUTHEAST CORNER OF INTERSECTION.
Advantages
· Provide for single intersection operation and better traffic flow.
· Right-of-way is acquired from one side
· Least impact on land development and use. Adequate access to abutting
properties.
Disadvantages
· Size of developable tract on the N.E. corner is reduced.
· Area between new and existing alignment of Beltline Road is too small
to develop and may have to be acquired by others.
Cost of Improvements
R.O.W. Cost
Improvement Costs
Signal Construction Cost
Engineering Design Cost
Total
$ 125,000
680,000
65,000
30~000
$900,000
City of Coppell
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ALTERNATIVE Itb, - REALIGN NEEDED ROADWAYS ON EAST APPROACH TO
MATCH LAND DEVELOPMENT PATTERNS AND ROADWAY ALIGNMENTS FOR
GATEWAY BUSINESS PARK, OPERATE AS A ONE- WAY ROADWAY SYSTEM
WITH TWO SIGNALIZED INTERSECTIONS
Advantages
· Provide ma]or roadway channelization to adequately
traffic flows.
· Access to abutting properties is adequate but limited.
handle future
Disadvantages
· Has a considerable impact on land and land development.
· Requires two signalized intersections.
· Roadway terminus requires additional R.O.W.
Cost of Improvements
R.O.W. Cost
Construction Costs
Signal Construction Cost
Engineering Design Cost
$ 275~000
580~000
100~000
45~000
Total $ 1,000,000
City of Coppell
Page
RECOMMENDATIONS:
Either alternative I or 2 can satisfactorily handle future traffic projections
with minimum negative land impacts. Alternatives 3 and ~ were eliminated
because of the excessive cost of improvements and higher impacts of land use
development.
Of the two alternatives~ alternative #1 causes problems for turning move-
ments and produces excess undevelopable land beyond those required for
street R.O.W.
Alternative tt2 requires cooperation of both property owners north and south
of Southwestern Dr. to properly replat the land and dispose of of street
R.O.W.'s.
Based on traffic movements through the intersection~ and land development
patterns and possible redevelopment~ alternative 112 roadway alignment is
recommended.