ST9602-SY 970131SCHEMATIC DESIGN REPORT
PROJECT #10
FOUR INTERSECTION IMPR0VEMEN'TS
IN THE CITY OF COPPELL
JANUARY, 1997
Unzicker, Schnurbusch & Assoc., Inc.
Dallas, Texas
SCHEMATIC DESIGN REPORT.
PROJECT #10
FOUR INTERSECTION iMPR 0 VEMENTS
IN THE CITY OF COPPELL
JANUARY, 1997
Prepared By:
Unzicker, Schnurbusch & Assoc., Inc.
Dallas, Texas
Introduction
The purpose of this schematic design report is to present the roadway schematic
improvement plan and to discuss the traffic analysis and design review findings
associated with four intersections located in the city of Coppell. This project provides for
the study, design, and construction of permanent intersection capacity improvements,
consisting of addition of exclusive left and fight turning lanes at each intersections.
The study intersections are listed below:
* Denton Tap at Bethel Road
* Denton Tap at Wrangler
* Belt Line at MacArthur
* Sandy Lake at Moore
This report summarizes the following items:
* Existing roadway geometry conditions,
* Proposed roadway improvements to the interchanges listed above,
* Design related issues associated with proposed improvements, and
* Preliminary design exceptions for each project.
Accompanying this report is:
* Schematic roll drawings of each intersection.
SCHEMATIC DESIGN REPORT
FOR
DENTON TAP AT BETHEL
Description of Existing InterSection
Denton Tap Road is a north/south six lane divided roadway that intersects with Bethel
Road. Bethel Road west of Denton Tap is a two lane undivided roadway. Bethel Road
east of Denton Tap is a four lane divided roadway. North, south and westbotmd legs of
this intersection have exclusive left turn lanes. The comers on the eastside of Denton Tap
both have ADA ramps, but the Northwest and southwest comers do not have any ADA
ramps. Cross-walks are provided along the North, South and East legs of the intersection
but not provided on the west leg. Both the cross-walks and ADA ramps are constructed
with pavers. There is a bridge located just north of the intersection.
Description of Proposed Improvements
The proposed improvement is to add a 3.300 meter wide southbound right turn lane. The
required storage length for the right turn lane will be 45 meters with a 45 meter transition
length. The added width to the roadway will require that additional right-of-way be
purchased. A handicap ramp will be replaced at the Northwest comer of the intersection
and an existing storm sewer inlet located along Denton Tap just North of the intersection
will have to be relocated along the newly constructed right turn lane.. Where existing
brick pavers are located, they will be extended through the improvement.
Traffic Analysis
The geometric improvements proposed by the City of Coppell were tested to ensure that
Level of Service (LOS) fuel Consumption and .Intersection Delay were improved.
Analysis was based on 1996 turning movements counts and signal phasing provided by
the City of Coppell. The intersection was analyzed as an isolated intersection using
Passer I1-90. The existing and proposed improvement were evaluated before both AM
and PM peak periods. Level of Service, Fuel Consumption and Intersection Delay were
compared in order to determined if the improvement was a benefit to the operation of the
intersection. A table listing the Level of Service, Intersection Delay in addition to the
Passer 11-90 runs are included in Appendix A.
The determination of the length of turn lanes and transition was based on the appropriate
formulas~found in ASSHTO and leading Industry Handbooks. Lengths were calculated
based ~f/the posted speed limit of the roadway, lane widths and traffic volumes. In the
2
case of the fight turn lane at Denton Tap Road and Bethel Road a standard 45 meter
transition and 45 meter storage lane were recommended in order to meet future demand.
Utility Relocation
Miscellaneous utility adjustments will be required to accommodate the proposed
improvements. Utility adjustments include Signal pole, and drainage inlets. Minor
signing in the vicinity of the intersection will also require adjustment. No major utility
relocation's are anticipated.
Right - Of - Way Requirements
Adequate ROW is not available to accommodate the proposed improvements along the
southbound leg of Denton Tap. To minimize the ROW acquisition cost, and for the
purposes of this preliminary schematic, ROW dedications are shown h,a~s 2.000 meters
parallel to and behind the back of the curb or 3.880 meter from the existing ROW in the
areas where the pavement will be widened. In addition, a 6.0 x 6.0 meter comer clip will
be required. In the research that our surveyor was able to uncover, we found no ROW
dedication for the north side of Bethel Road west of Denton Tap. Our records show that
the ROW went to the centerline of Bethel Road, Therefore, we must assume for now that
additional ROW will be required for Bethel Road. Since this project was for a right turn
lane parallel to Denton Tap we did not include the cost for ROW along Bethel Road. If
the cost for ROW should be include, we would first need to know how far to the south the
ROW would be purchased? The land on the Northwest comer of the intersection belongs
to Alexander Investment Trust, Vol. 90065, Pg. 1902, D.R.D.C.T. according 16 our
investigation.
Per direction from Ken Griffin - City of Coppell on Febuary 20, 1997 a cost of $_2 per sq.
foot or $21.50 per sq. meter will be used for R.O.W. cost. The preliminary R.O.W.
acquisition cost is approximately $5,700 for a 265 square meter dedication as indicated in
the attached roll drawing. However, this does not include any R.O.W. along Bethel Road.
Project Cost
The project costs attached in Appendix B provide a detailed listing of the cost
components of this project. The construction, ROW and TxDOT construction
administration fees allotted for this intersection are approximately $30,000. Preliminary
Engineer' s Cost Opinion of $47,400 for construction, this estimate includes a
contingency factor of 10% for additional construction items that are yet to be identified at
this level of design completion. The ROW acquisition is estimated to be $5,700. These
costs plus $5,660 for the TxDOT construction administration fee provides a construction
budget shortfall of $38,139 as shown in Appendix C.
A savings of $2,800 for the cost estimate could be made if the right turning lane is
reduced to 3.000 meters and the storage length is reduce to 30 meters which may impact
the traffic and increase spillback. Even with these improvements, the budget will still
have a shortfall of $34,853.
This intersection can not be constructed for the current budget amount of $30 000.
Environmental Issues
This intersection is identified as a Programmatic Categorical Exclusion. This project is
not expected to significantly impact the surrounding land use, population, resources, or
the overall quality of life.
DESIGN CRITERIA
PRELIMINARY SCHEMATIC
Design Item Criteria Source
Posted Design Speed 60 KM/Hr City of Coppell
Through Lane Width 3.3 m AASHTO page 335
Turn Lane Widths 3.0 m AASHTO page 334
Curb Offset 0 m* AASHTO page 349
Intersection Radii 12 m AASHTO page 664 and Table 1X-3
based on WB- 15
Median Width 0.6 m AASHTO page 783
Median Opening Spacing 39 m AASHTO page 758 Table IX- 18
* The curb offset was eliminated to minimize the required right-of-way dedications.
The curb offset will be incorporated with the turn lane widths to provide the
minimum standard instead of the recommended standard.
4
SCHEMATIC DESIGN REPORT
FOR
DENTON TAP AT WRANGLER
Description of Existing Intersection
Denton Tap is a north/south six lane divided roadway, with an exclusive left tum lane in
the noahbound direction. Denton Tap is teed into by Wrangler, a two lane undivided
roadway. Concrete pavers are used to delineate pedestrian crosswalks.
Description of Proposed Improvements
The proposed improvement is to add a southbound right turn lane 3.300 meters wide.
The required storage length for the right turn lane will be 60 meters with a 50 meter
transition length. The added width to the roadway will require that additional right-of-
way be purchased. USA Inc. would proposed to only purchase 1.200 meters of additional
R.O.W. to reduce the impact of removing existing shrubs and oak trees planted along the
west side of Denton Tap. A handicap ramp will be placed at the northwest comer of the
intersection. Existing storm sewer appurtenances will need to be adjusted to the
appropriate location along the newly constructed right turn lane. Where existing brick
pavers are located, they will be extended through the improvements.
The geometric improvements proposed by the City of Coppell were tested to ensure that
Level of Service (LOS) fuel Consumption and Intersection Delay were improved.
~ ,4., Analysis was based on 1996 tuming movements counts and signal phasing provided by
the City of Coppell. The intersection was analyzed as an isolated intersection using
,/~ Passer II-90. The existing and proposed improvement were evaluated before both AM
and PM peak periods. Level of Service, Fuel Consumption and Intersection Delay were
,~.,?
compared in order to determined if the improvement was a benefit to the operation of the
intersection. A table listing the above measures and the Passer II-90 runs are included in
Appendix A.
The determination of the length of turn lanes and transition was based on the appropriate
formulas found in ASSHTO and leading Industry Handbooks. Lengths were calculated
based of the posted speed limit of the roadway, lane widths and traffic volumes. In the
case of the right turn lane at Denton Tap and Wrangler a standard 50 meter transition and
60 meter storage lane were recommended in order to meet future demand.
5
Utility Relocati0n
Miscellaneous utility adjustments will be required to accommodate the proposed
improvements. Utility adjustments include signal pole, traffic control box, and drainage
inlets. Minor signing in the vicinity of the intersection will also require adjustment. No
major utility relocation's are anticipated.
.Right - Of - Way Requirements
Adequate ROW is not available to accommodate ~he proposed improvements along the
southbound leg of Denton Tap. To minimize the ROW acquisition cost, and for the
purposes of this preliminary schematic, ROW dedications are shown has 1.200 meters
parallel to the existing ROW or 2.000 meter from the back of curb in the areas where the
pavement will be widened. In addition, a 9.0 x 9.0 meter comer clip will be required to
be able to include a reasonable amount of brick paver behind the curb but still inside the
ROW. The traffic control box will also be placed within this comer clip.
Per direction from Ken Griffin - City of Coppell on Febuary 20, 1997 a cost of $2 per sq.
foot or $21.50 per sq. meter will be used for R.O.W. cost. The preliminary R.O.W.
acquisition cost is approximately $2,700 for a 125 square meter dedication as indicated in
the attached roll drawing.
Project COst !D~;t f,~c , ~
_
The project costs attached in Appendix B provide a detailed listing of the cost
components of this project. The construction, ROW and TxDOT construction
administration fees allotted for this intersection are approximately $35,00~0_. Preliminary
Engineer's Cost Opinion' of $63,500 for construction, this estimate'Tncludes a
contingency factor of 10% for additional construction items that are yet to be identified at
this level of design completion. The ROW acquisition is estimated to be $2__,70_Q_0./T~'~i~
cost plus $7,582 for the TxDOT construction administration fee provides a construction
budget shortfall of $50,169 as shown in Appendix C.
A savings of $4,343 for the cost estimate could be made if the right turning lane is
reduced to 3.000 meters and the storage length is reduce to 30 meters which will greatly
impact the traffic and increase spillback. Ev?n with these improvements, the budget will
still have a shortfall of $45,072.
This instersection can not be constructed for the current budget amount of $35,000.
Environmental Issues
This intersection is identified as a Programmatic Categorical Exclusion. This project is
not expected to significantly impact the surrounding land use, population, resources, or
the overall quality of life.
DESIGN CRITERIA
PRELIMINARY SCHEMATIC
Design Item Criteria Source
Posted Design Speed 60 KM/Hr City of Coppell
Through Lane Width 3.3 m AASHTO page 335
Turn Lane Widths 3.0 m AASHTO page 334
Curb Offset 0 m* AASHTO page 349
Intersection Radii 12 m AASHTO page 664 and Table 1X-3
based on WB- 15
Median Width 0.6 m AASHTO page 783
Median Opening Spacing 39 m AASHTO page 758 Table 1X-18
* The curb offset was eliminated to minimize the required right-of-way dedications.
The curb offset will be incorporated with the turn lane widths to provide the
minimum standard instead of the recommended standard.
7
SCHEMATIC DESIGN REPORT
FOR
BELTLINE ROAD AT MACARTHUR
Description of Existing Intersection
Beltline Road is a five lane divided roadway on the west side of the intersection with an
exclusive right and left turn lane in the eastbound direction. ~3eltline Road, on the east
side, is a five lane divided roadway with exclusive dual-~i~tum lanes in the westbound
direction. Beltline intersects MacArthur, which is a four lane divided roadway, with an
exclusive left turn lane on the northern leg and a five lane divided roadway with an
exclusive left turn lane on the south leg. From 6-9 a.m. the southbound inside through
lane changes to a shared left/through lane. The northern leg of MacArthur is crossed by
a railroad track just noah of the intersection. The entire intersection is made up of
concrete pavers.
Description of Proposed Intersection
The proposed improvement is to add a southbound left turn lane 3.000 meters wide. The
width of the turning lane was reduced to 3Z000 meters from 3.300 meters to reduce the
impact to the existing median along MacArthur Boulevard. No additional fight-of-way
will be required because of the additional lane being expanded to the inside. The required
storage length for the left turn lane will be 60 meters with a 50 meter transition length.
Handicap ramps will be constructed at the southwest and northwest comers of the
intersection. The railroad crossing arms will have to be relocated along with other
equipment. · Utilities of mention are a major petroleum line and fiber optic cable. Any
sidewalks disturbed by the construction will have to be replaced. Where existing brick
pavers are located, they will be extended through the improvements. One alternative that
was looked at by the designer was to consider adding a right turn lane along the northern
leg. However the traffic counts did not justify that type of improvements at this time.
Traffic AnalySis
The geometric improvements proposed by the City of Coppell were tested to ensure that
Level of Service (LOS) fuel Consumption and Intersection Delay were improved.
Analysis was based on 1996 turning movements counts and signal phasing provided by
the City of Coppell. The intersection was analyzed as an isolated intersection using
Passer 11-90. The existing and proposed improvement were evaluated before both AM
and PM peak periods. Level of Service, Fuel Consumption and Intersection Delay were
compared in order to determined if the improvement was a benefit to the operation of the
intersection. A table listing the above measures and the Passer 11-90 runs are included in
Appendix A.
The determination of the length of turn lanes and transition was based on the appropriate
formulas found in ASSHTO and leading Industry Handbooks. Lengths were calculated
based of the posted speed limit of the roadway, lane widths and traffic volumes. In the
case of the left turn lane at MacArthur and Beltline Road a standard 50 meter transition
and 60 meter storage lane were recommended in order to meet future demand.
Utility Relocations
Miscellaneous utility adjustments will be required to accommodate the proposed
improvements. Utility adjustments include signal poles, railroad signals and crossing
arms. Minor signing in the vicinity of the intersection will also require adjustment. No
major utility relocations are anticipated.
Right-Of-Way Requirements
No fight-of-way is anticipated do to the improvement all occurring along the i/~side
median.
Project Cost
The project costs attached in Appendix B provide a detailed listing of the cost'
components of this project. The construction, ROW and TxDOT construction
administration fees allotted for this intersection are approximately $90,000. Preliminary
Engineer'SCost Opinion of $47,600 for construction, this estimate includes a
contingency factor of 10% for additional construction items that are yet to be identified at
this level of design completion. These cost plus $5,683 for the TxDOT construction
administration fee provides a constructionCo_udg. et_t~s.surplus of $1 3 ,708~as shown in
Environmental Issues
This intersection is identified as a Programmatic Categorical Exclusion. This project is
not expected to significantly impact the surrounding land use, population, resources, or.
the overall quality of life.
9
DESIGN CRITERIA
PRELIMINARY SCHEMATIC
Design Item Criteria Source
Posted Design Speed 60 KM/Hr City of Coppell
Through Lane Width 3.3 m AASHTO page 335
Turn Lane Widths 3.0 m AASHTO page 334
Curb Offset 0 m* AASHTO page 349
Intersection Radii 12 m AASHTO page 664 and Table 1X-3
based on WB- 15
Median Width 0.6 m AASHTO page 783
Median Opening Spacing 39 m AASHTO page 758 Table 1X-I 8
* The curb offset was eliminated to minimize the required fight-of-way dedications.
The curb offset will be incorporated with the turn lane widths to provide the
minimum standard instead of the recommended standard.
10
SCHEMATIC DESIGN REPORT
FOR
SANDY LAKE ROAD AT MOORE ROAD
Description of Existing Intersection
Sandy lake Road is an East/West two lane undivided roadway, It intersects with Moore
Road a two lane undivided roadway. Moore Road south of the intersecting flares out as
you are approaching from the South. Traffic buttons are arranged so there is an exclusive
left turn lane. Moore north of the intersection has an expanded cross-section that lasts
about 100 feet before narrowing to its typical cross-section. Pavers are in place for future
crosswalks both north and south of the intersection along Moore Road. The sidewalk
along the southeast leg is set back from the roadway so that a roadside ditch may drain
under the existing driveways.
Description of Proposed Improvements
The proposed geometric improvement involves widening Sandy Lake to a four lane
divided with exclusive left turn lanes for both east and west bound traffic. Moore Road
to the south will remain the same overall width but will now be utilized as a four lane
undivided. Moore Road north of the intersection has recently been expanded to a four
lane undivided roadway. The length of the construction along Sandy Lake Road will be
175 meters.
Traffic Analysis
The geometric improvements proposed by the City' of Coppell were tested to ensure that
Level of Service (LOS) fuel Consumption and Intersection Delay were improved.
Analysis was based on 1996 turning movements counts and signal phasing provided by
the City of Coppell. The intersection was analyzed as an isolated intersection using
Passer II-90. The existing and proposed improvement were evaluated before both AM
and PM peak periods. Level of Service, Fuel Consumption and Intersection Delay were
compared in order to determined if the improvement was a benefit to the operation of the
intersection. A table listing the above measures and the Passer 11-90 runs are included in
Appendix A.
The determination of the length of turn lanes and transition was based on the appropriate
formulas found in A~SHTO and leading Industry Handbooks. Lengths were calculated
based of the posted speed limit of the roadway, lane widths and traffic volumes. In the
case of the left turn lanes located on Sandy Lake in both directions a standard 45 meter
transition and 45 meter storage lane was recommended in order to meet future demand.
11
Utili.ty Relocation
Utility adjustments will be required to accommodate the proposed improvements. Utility
will be completely redone in conjunction with plans currently being produced by Kimley
- Horn & Assoc. in their Fort Worth office. These plans do not account for the cost of the
water lines, sanitary sewer lines and drainage structures except for the cost of the required
inlets and laterals within the project limits. Minor signing in the vicinity of the
intersection will also require adjustment.
Right - Of - Way Requirements
Adequate R.O.W. is not available to accommodate the proposed improvements along
Sandy Lake Road. R.O.W. dedications ,,ar-~shown has 8.027 meters parallel to and behind
the back of the North curb line and 2.643 meters'parallel to and behind the back of south
curb line. The pavement will be widened in addition to the 42 square meter comer
required on the North side of Sandy Lake Road and the 10.5 square meter comer clips
required on the South side of Sandy Lake Road. The required R.O.W. taking is to match
the R.O.W. shown in the Kimley - Horn & Assoc. plans. The Kimley - Horn plans show
a parkway on the Northside of Sandy Lake Road of 10 feet or 3.048 meters and a
parkway on the Southside of Sandy Lake Road of 15 feet or 4.572 meters behind the back
of curb.
Per direction from Ken Griffin - City of Coppell on Febuary 20, 1997 a cost of $2 per sq.
foot or $21.50 per sq. meter will be used for R.O.W. cost. The preliminary R.O.W.
acquisition cost is approximately $39,000 for a 1814 square meter dedication as indicated
in the attached roll drawing.
Project Cost
The project costs attached in Appendix B provide a detailed listing of the cost
components of this project. The construction, R.O.W. and TxDOT construction
administration fees allotted for this intersection are approximately $514,000. Pre!i~ina~..
Engineer's Cost Opinion of $322,388 for construction, this estimate includes a
contingency factor of 10% for additional construction items that are yet to be identified at
this level of design completion. These plans__d0_' not account fo[the cost 9f the water
lines, sanitary sewer lines and drainage structures excel.for ~h~ qq~t_pf~h~.ye__cLU~ir_e.~. i~_!~ys
and laterals within the project limits. The cost of the water lines, sanitary sewer lines and
'drainage structures will be covered under the Kimley - Horn plans. The R.O.W.
acquisition is estimated to be $39,000. These cost plus $38,493 for the TxDOT
coiiit~ction administration fee provides a construction budget shortfall of $2~,027 as
shown in Appendix C. ~, ,., ~ -, ~ ,, ~ ~ ~
12 .~r~4~!,~
This cost estimate does not include any cost for temporary roadway construction because
the plans by Kimley -Hom will be constructed at the same time.
Environmental Issues
This intersection is identified as a Programmatic Categorical Exclusion. This project is
not expected to significantly impact the surrounding land use, population, resources, or
the overall quality of life.
PRELIMINARY SCHEMATIC
DESIGN CRITERIA
Design Item Criteria Source
Posted Design Speed 60 KM/Hr City of Coppell
Through Lane Width 3.3 m AASHTO page 335
Turn Lane Widths 3.0 m AASHTO page 334
Curb Offset 0 m* AASHTO page 349
Intersection Radii 12 m AASHTO page 664 and Table 1X-3
based on WB - 15
Median Width 0.6 m AASHTO page 783
Median Opening Spacing 39 m AASHTO page 758 Table 1X- 18
* The curb offset was eliminated to minimize the required fight-of-way dedications.
The curb offset will be incorporated with the turn lane widths to provide the
minimum standard instead of the recommended standard.
13