ST9302-AG010430~6,pi~iL AGENDA REQUEST FORk{
~ ~'~'~ ~ q CITY COIJNCIL MEETING: April 30, 2001 ITEM #
ITEM CAPTION:
Consider approval of a variance to the Subdivision Ordinance No. 94643 Appendix C, Section I, paragraph
F.2. entitled "Intersection Treatment", paragraph F.4. entitled "Pavers", Appendix D, Section VI, paragraph B
entitled "Intersection Design", and Section VIII, paragraph A entitled "Pavers" to allow the use of paving
materials other than "Brick Pavers" for the Sandy Lake Road/MacArthur Blvd. intersection.
APPROVED
SUBMITTED ~KennethM. Griffin, P.E. '~ % CITYCOUNCIL
TITLE( Director of Engineering/V~u.b..ljs>Works DATE 4 -.~o -- n t .
STAFF COM2VIB~TS: ............... '"' ~ ~ ~
See attached memo. ~ ~
BUDGET AMT $ AMT EST. $ +k-BID $
FINANCIAL COMMENTS:
Agenda Request Form - Revised 5/00 Document Name: #engl
Item # 3
Move to approve a variance to Subdivision Ordinance No. 94643, Appendix C,
Section I, paragraph F.2 entitled "Intersection Treatment", paragraph F.4. entitled
"Pavers", appendix D, Section VI, paragraph B entitled "Intersection Design",
and Section VIII, paragraph A, entitled "Pavers" to allow the use of paving
materials other than "Brick Pavers" for Sandy Lake Road/MacArthur Blvd
intersection with the following conditions:
(1) the majority of the intersection will be paved with standard concrete,
(2) the aesthetic accents to the intersection will be paved with stamped
concrete at a price not to exceed the amount allotted for brick pavers in the
original contract,
(3) The city engineering staff will be the final authority responsible for the
design and placement of the stamped concrete accents.
MEMORANDUM
FROM THE
DEPARTMENT OF ENGINEERING
To: Mayor and City Council Members
From: Kenneth M. Griffin, P.E., Dir. of Engineering/Public Works ~
Date: April 30, 2001
RE: Consider approval of a variance to the Subdivision Ordinance No. 94643 Appendix C,
Section I, paragraph F.2. entitled "Intersection Treatment", paragraph F.4. entitled
"Pavers", Appendix D, Section VI, paragraph B entitled "Intersection Design", and
Section VIII, paragraph A entitled "Pavers" to allow the use of paving materials other
than "Brick Pavers" for the Sandy Lake Road/MacArthur Blvd. intersection.
At the April 24, 2001 City Council meeting, discussion was held during work session concerning the
elimination of"brick pavers" as a requirement as outlined in the City's Subdivision Ordinance. During the
course of the discussion, it was decided that an agenda item would be brought forth to specifically deal
with the MacArthur/Sandy Lake Road intersection as it pertains to the utilization of "brick pavers". This
agenda item is a variance request to various sections of Subdivision Ordinance #94643 that require the
utilization of "brick pavers".
Appendix C, Section I, paragraph F.2. states "all paving in major, secondary and minor intersections shall
be constructed in accordance with standards in the City's Streetscape Plan." It further states "concrete
pavers shall be used in both street and sidewalk construction." I have included Figure 2 from the City's
Streetscape Study, which shows the major, secondary and minor intersections throughout the City of
Coppell. The intersection in question is a major intersection.
Appendix C, Section I, paragraph F.4. provides information pertaining to the type of paver to be used in
the major, secondary and minor intersections. Paragraph 4 also goes on to state "other alternative paving
materials or methods of installation may be approved if they are comparable in quality, color, texture and
integrity to the City's standards assigned to pavers."
Appendix D, Section VI, paragraph B states "major intersections should be a full paver intersection if
practical." The detail for the full paver intersection is provided. This detail shows the banded full
intersection with the contrasting "brick paver" throughout the entire intersection.
Appendix D, Section VIII, paragraph A provides further information concerning the paver to be utilized
for intersections.
There are three issues concerning the use of "brick pavers" 1) aesthetics, 2) cost, and 3) long-term
maintenance. The aesthetic issue is addressed in the City's Streetscape Plan as an attempt to set Coppell
apart from other communities. Most intersections within the City of Coppell have "brick pavers" either
entirely or banded.
"CITY OF COPPELL ENGINEERING o EXCELLENCE BY DESIGN"
The cost issue is difficult to determine at this time, however, the contractor has stated that the full depth
color, "stamped concrete" would be provided at a cost of $71.29/per square yard. The cost for the "brick
pavers" in the contract was $58.00/per square yard. The cost for basic concrete paving was $24.88/per
square yard. There is approximately 2100 square yards of pavers within the MacArthur Blvd./Sandy Lake
intersection. The cost difference from "brick pavers" to "stamped concrete" is $13.29/per square yard.
For the entire intersection this equates to an increased cost of $27,909.
If Council approves the concept of the utilization of stamped concrete in lieu of "brick pavers", a Change
Order would need to be approved by Council because the value of the change is greater than $25,000.
That item is also included on this agenda. The reason that item is included on this agenda is because of
the timing of providing direction to the Contractor if Council supports the change from "brick pavers" to
"stamped concrete". The Contractor is preparing to mobilize in the first week of May. The long-term
maintenance issue involves numerous locations throughout our community which have experienced
failure of the pavers as they abut the adjoining concrete. This is not a problem only in Coppell. The
pavers installed on S.H. 121 Bypass have experienced substantial failures and are in the process of being
removed and replaced with asphalt. Because of the time involved in performing the repair of the brick
pavers, the initial reaction to an unsafe condition is to provide a temporary asphalt patch. Once personnel
are allocated to repair the pavers, the asphalt patch along with the pavers are removed, the subsurface is
repaired and the pavers are replaced. Once the failure has occurred in "brick pavers", it typically tends to
fail more than once. This is not due to the workmanship on the repair, it is typically due to the fact that
the underlying concrete has cracked or deteriorated in some form allowed the migration of bedding sand,
therefore creating voids under the pavers, which allows them to fall.
In some repairs in years past, we have sealed the underlying concrete only to yet again have the pavers
fail. Because of the continual failures along MacArthur, I have proposed in my 5-year plan a pilot
program to begin removing and replacing the "paver bands" along MacArthur Blvd. with "stamped
concrete".
The actual cost of the "stamped concrete" verses "brick pavers" is a difficult number to ascertain. If
"stamped concrete" were bid with the project you would have attained a variety of pricing. The Sandy
Lake Road project had a value of "brick pavers" ranging from $44.55 to $65.00/per square yard. Bidders
adjust the cost of various bid items as they bid a project. We did utilize "stamped concrete" on the road
humps on Town Center Drive (Sonic or 2na Access to High School, if you prefer). The value of that
stamped concrete was more in the range of $35 to $40/per square yard.
I contacted the local company, North Texas Bomanite to inquire about the cost of the intersection
improvements with "stamped concrete". I was informed that their actual pricing for "stamped concrete"
was in the range of $68 / per square yard. When I questioned why it was so high, the vice-president stated
that the cost is a factor of several things. One is that to construct an intersection and maintain traffic you
typically have 4 to 6 move-ins to perform the stamped concrete work. Because of that, the sections being
poured at any given time are smaller, therefore, hand pours are used. Also, the traffic needs to be
maintained so there is extensive traffic control involved in working within the intersection. The material
costs for the full depth adds approximately $10 - $11/per square yard to the cost of the stamped concrete.
The alternate to this is to go to a surface color, however, the potential exists for it to wear off over a period
of time.
"CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN"
The item before you is to allow the utilization of "stamped concrete" in the MacArthur/Sandy Lake
intersection. The request is brought forth at this late date as we have been attempting to obtain pricing for
some time. Also, the contractor has indicated that the utilization of "stamped concrete" could save as
much as one and one/half to two months off the construction time of the MacArthur/Sandy Lake
intersection. The life of the stamped concrete should be comparable to concrete streets throughout
Coppell.
With this agenda item I have also included a fax from North Texas Bomanite showing various locations
where full color crosswalks are being utilized.
Staff will be available to answer any questions at the Council meeting.
"CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN"
SLrBDIVISION REGULATIONS - CITY OF COPPELL. TEXAS
APPENDIX C - DESIGN CRITERIA AND STANDARDS
SECTION I - STREETS AND ALLEYS
Coppell Parks, Recreation and Open Space Master Plan and the
approved City Hike/Bike Trail Plan. Sufficient additional right-of-way
and easements shall be dedicated for construction of paths and trails.
F. Landscaping Treatment Requirements
1. Median Treatment. All medians shall be landscaped and irrigated with an
irrigation system in accordance with the approved City Streetscape Plan.
The irrigation system shall be designed and installed in such a fashion as to
prevent its operation at times of freezing or subfreezing temperature. When
a Developer is responsible for the construction of a median opening and left
turn lanes in the median, he shall also be responsible for all the costs
associated with the required landscaping in those portions of the medians
affected by the opening. Any changes made in the landscaping or irrigation
system must be approved and indicated on the plans as built/installed, and
Developer shall also repair/replace any element of the area affected by his
project, returning the area to its condition prior to his commencing his
project. Any and all changes must be approved by the licensed landscape
irrigator.
2. Intersection Treatment. All paving in major, secondary, and minor
intersections shall be constructed in accordance with standards established
in the approved City Streetscape Plan. Concrete pavers shall be used in
both street and sidewalk construction. Landscaping at the corners shall
conform to the standards in the Streetscape Plan as well as the visibility
requirements of this document and the City Zoning Ordinance.
3. Edge and Subdivision Entry Treatment. Landscaping shall be designed in
accordance with the approved City of Coppell Streetscape Plan and with the
appropriate sections of the City Zoning Ordinance. In residential
subdivisions, the Developer shall establish a home owners association to
maintain the required screening walls along major/minor arterial and
collectors, the landscaping between the walls and the sidewalk and any
landscaping/signage at subdivision entry features. The association shall also
be responsible for maintaining common area landscaping adjacent to
drainage channels. In non-residential subdivisions, the Developer may
establish a property owners association to maintain the required common
area edge landscaping and entry features. If one is not established, it shall
become the responsibility of the property owner to maintain the landscaping
in conformance with Section 33 of the City Zoning Ordinance. Subdivision
entry features will not be allowed unless a mechanism for maintenance, such
as a property owners association, is established. Whenever a home or
i property owners association is established to maintain required landscaping,
Page 84
SUBDIVISION REGULATIONS - CITY OF COPPELL. TEXAS
APPENDIX C - DESIGN CRITERIA AND STANDARDS
SECTION I - STREETS AND ALLEYS
the by-laws shall be approved by the Planning and Zoning Commission and
City Council when the final plat is submitted for approval.
4. Pavers. Interlocking concrete pavers or other approved pavers are required
at all entries to Subdivisions, Commercial shopping centers, and Industrial
parks. Pavers are also to be used at major, secondary, and minor
intersections according to guidelines set forth in the approved Streetscape
~Plan, and to delineate all pedestrian/bike path crossings at streets. Pavers
shall be selected in conformance with standards set forth in the approved
~ity Streetscape Plan. The City standard paver is Pavestone "Uni-Decor"
interlocking or approved equal. The paver is approximately 3 1/8' thick,
pigmented and the following color application shall be followed:
Intersections shall be antique red as a standard, although dark grey is to be
used in the center and light grey as accent banding. Accent banding is to be
4" x 8' rectangular paver, 'Holland Stone" or approved equal.
Concrete pavers must be saw cut. Block cutters shall not be permitted. All
pavers are to be set into a 1' sand leveling bed, on a sub-base of reinforced
concrete paving, as per the City of Coppell Standard Construction Details
unless alternative paving materials or methods of installation are approved
by the City Engineer. _.They shall be acceptable, if they are comparable in
quality, color, texture, and integrity to the City Standard assigned to pavers.
5. Technical Specifications. Installation of landscaping and irrigation system
shall be as specified by the landscape architect or landscape contractor that
belongs to a bonafide Nurseryman's Association and as approved by the
City of Coppell.
END OF SECTION
Page 85
SUBDIVISION REGLq. ATIONS - CITY OF COPPELL. TEXAS
APPEN-DIX D - STREETSCAPE PLAN
SECTION VI - STREETSCAPE DEVELOPMENT CONCEPTS
Primary City Image Zones Secondary City Image Zones
Denton Tap Road Bethel Road
Belt L':ne Road Moore Road
Sandy Lake Road Freeport Road
MacArthur Boulevard Parkway Boulevard
Thweatt Road
Each Primary Zone thoroughfare should be a divided thoroughfare with a 15 foot
median. Cedar Elms will be the dominant street tree in the median and edges,
accent~ with Redbud and Wild Plum and accent overstory trees of Sweet Gum or.
Chinese Pis,ache. Median noses at left turn lanes will be covered with interlocking
pavers interspersed by 18 ~ Juniper planting beds. Crape Myrtles above Honeysuckle
planting beds will also accent each end of the Median (Figure 3).
Secondary Zone thoroughfares will have a similar landscape scheme, but medians are
not a necessity and the roads should be only of a four lane capacity. If a median is
used, Bradford Pear will be the accent tree instead of Crape Myrtle and Liriope will
be used for ground cover below the Bradford Pears. Each median for Primary and
Secondary Zones will also be accented by Pampas Grass in the transition zone.
Pedestrian/bike path crossings at streets will be defined by red concrete pavers.
B. Intersection Design
Intersection designs have been developed for three types of intersections: major,
secondary and minor· These three types are identified and located on the Landscape
Opportunities map (Figure 2). Major intersections should receive top priority in
terms of streetscape implementation.
The design of major and secondary intersections should have consistent landscape
elements to include a 12~ high planting bed for annual and perennial flowers,
background plantings of pink and white Crape Myrtles to highlight the bed, and
accent overstory trees of Sweet Gum and Chinese Pistache. Crosswalks 15 feet wide
shall be constructed in red interlocking concrete pavers with light gray concrete
pavers delineating the edges of the crosswalks. The pavers will also be used on the
corners where pedestrians will be standing. ,The center of major intersections should
be highlighted by a dark gray concrete paver (Figure 4A) if engineering proves
~,racUcal.
The third level of intersection design is used to define minor intersections.
Crosswalks are eight feet wide and shall be constructed in the concrete pavers with
no edge banding. Planting beds are not utilized and no special landscaping is
required (Figure 5).
Page 115
SUBDIVISION REGULATIONS - CITY OF COPPELL. TEXAS
APPENDIX D - STREETSCAPE PLAN
SECTION VHI - STREET HARDWARE AND SPECIAL LANDSCAPE ELEMENTS
VIII. STREET HARDWARE AND SPECIAL LANDSCAPE ELEM~ENTS
The term "street hardware" refers to the man-made elements found within or adjacent to the
street right-of-way. These include pavers, street lights, traffic signals, telephone/electric poles,
and traffic signage. Benches and street furniture have not been included in this study.
A. Pavers: The City standard paver for use at intersections, City entry points, at
development/subdivision entry features and to delineate all pedestrian/bike path
crossings of streets is the interlocking paver "Uni-decor" manufactured by Pavestone
(or its equal)_. Antique red shall be the standard color, although dark gray pavers will
be used for centers of intersections and a light gray will be used for accent banding.
Ac. cent banding will be accomplished using 4" by 8" rectangular paver, "Holland
Stone" (or equal). All pavers are + 2 1/2" thick pigmented concrete pavers set on
a 1" sand leveling bed. The subbase shall be reinforced concrete paving, unless
another material is approved by the City Engineer. Alternate paving materials at
subdivision/development entry shall be acceptable if they are comparable in color,
quality and texture to the City standard.
B. Street Lights: Research into the possibilities of recommending a traditional fixture
to T.U. Electric for use in the street right-of-way indicated that the chances for
approval by T.U. are extremely slim. Without T.U. approval for a particular fixture,
the City would be responsible for providing, maintaining, and financing the electric
usage of these non-standard fixtures. The 20' and 30' KlM fixtures, presently
required by the City and provided by T.U., are therefore recommended as the best
alternative for public street lighting. Their simple design and dark brown duranodic
finish are compatible with most architectural styles and land use. The more
traditional light fixtures would be appropriate for individual projects/developments.
The property owner/developer would then be responsible for installing, maintaining
and paying for the electric use for these traditional fixtures.
C. Traffic Signals: The recommended traffic signal design (Figure 16) was selected to
be compatible with the approved City street lights. Both are simple in shape,
structurally stable and can be finished in dark brown duranodie or black to match the
approved City street lights.
~" D. Telephone and Electric Poles: As evidenced by the Subdivision Ordinance, the City
intends to limit the presence of telephone, power and television cable along the street
edge. Either underground or rear alley access lines are to be established in all
developments. Where alley access lines cross side streets, the City Engineer has
recommended to T.U. that simply designed metal support poles be used and set back
from the street to minimize any view of the poles/wires. It is also recommended that
the metal poles be painted to match the finish on the approved City street lights.
Page 123
COPPELL STREETSCAPE STUDY
) COPPELL STREETSCAPE STUDY .... ,".,,.,.~... 4----
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