ST8804-CS 890502 (2)Jerry Parchd Consulting Engineers
May 2, 1989
Mr. Russell Doyle, P.E.
City Engineer
City of Coppell
P O Box 478
Coppell, Texas 75019
214/462-0022
RE:
JP No. 88009; Heartz Road; Sight Distance at
Sandy Lake Road; Coppell, Texas
Dear Russell:
This letter will confirm the results of our meeting on May 2,
1989 regarding the sight distance in Heartz Road to be provided
at the Sandy Lake Road intersection with proposed grades in
Heartz Road north of Sandy Lake Road shown on construction plans
prepared by our firm. Present at the meeting were
Mr. Russell Doyle, P.E., City Engineer, City of Coppelt
Mr. Steve Goram, Director of Public Works, City of Coppell
Mr. Kevin Peiffer, P.E., Ginn, Inc. - Consultants to Coppell
Mr. Jerry Parche' P.E., Consulting Engineer
Issues regarding sight distance at the referenced intersection
were previously addressed in a report to you prepared by our firm
which was submitted to the City on April 13, 1989. This report
was reviewed on behalf of the City by Ginn, Inc. Comments
prepared by Ginn were presented in a report to the City prepared
by Mr. Peiffer dated April 21, 1989.
FUTURE CONDITIONS - IMPROVED SANDY LAKE ROAD.
Mr. Peiffer and I have agreed that the proposed grade of Heartz
Road north of Sandy Lake Road prepared by our firm would permit
design of a future grade through the intersection across Sandy
Lake Road such that safe sight distance is afforded drivers
travelling through the intersection on Heartz Road at design
speed. This design should require little if any reconstruction
of improved Heartz Road. Therefore sight distance conditions
following signalization of the intersection and improvements in
Sandy Lake Road will be in compliance with AASHTO minimums for
the anticipated design speed in Heartz Road through the
intersection.
320 9Vestway Place, Suite 501 · Arlington, Texas 76018 · Metro (817) 467-2418 · (817) 465-0259
Mr. Russell Doyle, P.E. May 2, 1989
JP No. 88009 Page 2 of 3
CONDITIONS WITH UNIMPROVED SANDY LAKE ROAD.
If traffic controls at the intersection allow vehicles in Heartz
Road to travel through the intersection at a design speed of 35
m.p.h, with existing Sandy Lake Road and proposed grades in
Heartz Road north of Sandy Lake Road, sight distance in Heartz
Road through the intersection will be less than the minimum
determined by AASHTO standards due to the existing "hump" in the
Sandy Lake Road cross section. This hump will most likely cause
drivers to reduce speed, regardless of sigh~ distance, in order
to maintain control of their vehicle.
There are no current plans to improve Sandy Lake Road or to
signalize the Heartz Road - Sandy Lake Road intersection.
However, in order to provide for safe manuvering of Heartz Road
traffic through the intersection, all traffic on Heartz Road will
be required to stop before proceeding across or turning onto
Sandy Lake Road following construction of Heartz Road north of
Sandy Lake Road.
Alternatives were discussed for providing sight distance
conditions in Heartz Road in compliance with AASHTO criteria in
the event signalization of the intersection is warranted prior to
improvements in Sandy Lake Road. With signalization vehicles
travelling in Heartz Road will have opportunities to proceed
through the intersection at design speeds, although the existing
Sandy Lake Road cross section may create control problems.
One alternative discussed for providing adequate design speed
sight distance in Heartz Road through the intersection was to
raise the proposed grade in Heartz Road north of Sandy Lake Road.
However, as suggested by Mr. Peiffer in his letter to you of
April 21, 1989, this would create a burden on the development of
adjacent land due to the difference in elevation of Heartz Road
and the elevation of these properties. In addition the hump in
Sandy Lake Road would continue to pose a safety problem.
It was generally agreed that the proposed grade of Heartz Road
north of Sandy Lake Road is appropriate for anticipated future
grading in the intersection. It was also agreed that plans for
signalization of this intersection with proposed grades in Heartz
Road north of Sandy Lake Road, if implemented prior to
improvements in Sandy Lake Road, should include
That signalization prevent movement of northbound and
southbound traffic in Heartz Road at Sandy Lake Road,
either turning left or proceeding through the
intersection, from occuring at the same time.
Mr. Russell Doyle, P.E. May 2, 1989
JP No. 88009 Page 3 of 3
Therefore southbound traffic in Heartz Road will be
allowed to turn left or proceed across Sandy Lake Road
while all northbound traffic at the intersection is
stopped, and vice versa.
o
In order to remove the hazard and limited sight
distance caused by the existing hump in Sandy Lake Road
to traffic travelling at design speed on Heartz Road,
local regrading of Sandy Lake Road at the Heartz Road
intersection should be performed concurrent with
signalization. This regrading should yield sight
distance in Heartz Road in compliance with AASHTO
criteria.
As we discussed in our meeting, we have included notes on our
construction plans to indicate the need for implementation of
traffic control devices, both at present and with future
signalization, to alleviate sight distance problems at the Heartz
Road intersection.
Also I would like to take this opportunity to correct the phrase
"south side of Sandy Lake Road" used in the second to last
paragraph of our report on sight distance at the Sandy Lake Road
- Heartz Road intersection dated April 12, 1989. This phrase
should have been "north side of Sandy Lake Road".
This letter provides my understanding of our resolution of the
sight distance issues at the Heartz Road - Sandy Lake Road
intersection as pointed out by Mr. Peiffer in his letter to you
of April 21, 1989 and discussed in our meeting of May 2, 1989.
If you, Mr. Peiffer, or Mr. Goram have any disagreements with or
wish to comment on the contents of this letter, please advise me
in writing. Thank You.
Sincerely,/-]
Jerry Pa/rch~e ,~P.E.
JP: ch
cc:
Mr. Jay Chester, P.E./ABQ Development Corporation
Mr. Steve Goram/ City of Coppell
Mr. Kevin Peiffer, P.E./Ginn, Inc.