ST9304-CS 941128DALLAS COUNTY
PUBLIC WORKS
November 28, 1994
Mr. Patrick L. Kunz, P.E.
Halff Associates, Inc.
8616 Northwest Plaza Drive
Dallas, Texas 75225
Re:
Belt Line Road -- Project No. 490-403.1 / 91-829
Denton Tap Road to MacArthur Boulevard
Geometric Alignment Study
Dear Mr. Kunz:
Attached is the Geometric Alignment Study submitted for review.
Please address the comments on the plans and in this letter and
submit the revisions by December 12, 1994. Re-submittals to the
County should include the original marked set of plans and should
address every comment on the plans and in this letter either by a
change in the plans or by discussion in the submittal letter.
The County was pleased to note the promptness and completeness of
your alignment study. Please call me at 653-7151 if you have any
questions concerning the project.
Sincerely,
xc: Ken Griffin, P.E., A:~sistant City Manager/City Engineer, City
of Coppell
Attachment
6. 0829/ALIGN. LTR
411 Elm Street Dallas, Texas 75202 653-7151
COMMENTS
10.
11.
Add a line representing the outer boundary of
easement necessary for 4:1 maximum slopes for
evaluation of possible additional easements.
the slope
Coppell's
Modify the typical section from 22' F-F to 24' F-F.
the median width accordingly.
Reduce
The County specifies a 550 psi flexural strength pavement
requirement (third point loading), not a compressive strength
requirement.
Draw and label City Limit Lines in the plan view.
Use consistent K values throughout the project.
curves should not overlap.
K sag = 100
K crest = 150
Vertical
Verify stationing, curve data, labeling and positioning of the
horizontal curve immediately east of Moore Road.
The Grapevine Creek Bridge should be designed to allow for the
ultimate 6 lane configuration including the left turn lane
geometrics for Mockingbird Lane. Due to the sight distance
requirements between Northlake Road and Mockingbird Lane, the
single bridge over the creek is approved.
Provide 2' of freeboard between the low chord of the bridge
and the 100 year water surface elevation of Grapevine Creek.
Comply with the Coppell standards requiring the top of curb be
no less than I foot above the 100 year flood elevation.
The County agrees with the preliminary storm sewer trunk line
location and the preliminary sequencing of construction.
The extra wide median opening at Moore Road is .approved
pending concurrence from Coppell.
Coppell will provide alignment approval after the above
comments have been addressed and after evaluation of the
slopes required by the 4:1 maximum slope standard.