TR9701-CS 970310Sverdrup
Civil, Inc. - Dallas, Texas Office
4311 Oak Lawn · Suite 300 · Dallas, TX 75219 · Tele: (214) 520-2116
· Fax: (214) 521-3539
MEETING MEMORANDUM NO. 13776-1
March 10, 1997
MEETING DATE: January 18, 1997
LOCATION:
City of Coppell
255 Parkway Boulevard
1 st Floor Conference Room
PARTICIPANTS:
Atul Patel
Brent Adams
Kathy Mullins
Jesse Hembree
Tony Tramel
Mark Goode
Jeremy Wyndham
City of Coppell
City of Coppell
City of Irving
City of Irving
DeShazo, Tang & Associates
Sverdrup Civil
Sverdrup Civil
SUBJECT:
Dallas County CMAQ Program
Project 75
Progress Review Meeting 1
Status of Field Observations:
· Field observations are complete. Time spacing of traffic signals has been recorded. Existing
controller time sheets from each of the existing traffic signals have been provided by the
Cities of Irving and Coppell. The only timing plan missing is the "Free Plan" (7:30 - 8:15
AM) for Denton Tap and Parkway. We have discussed the current and past phasing plans
along the corridor with both cities.
Status of Intersection Geometries:
· Photographs have been taken and intersection geometries have been noted.
Status of Data Collection:
· The start of the data collection was delayed due in part to bad weather in January and in part
due to the unavailability of count personnel. Travel time runs, machine counts and most of
the turning movement counts are complete. We expect to be complete with the rest of the
turning movement counts by the end of this week.
Dallas County CMAQ Program
Project 75
February 18, 1997
Page 2
Discussion of Control Area Boundaries:
Based on field observations and a preliminary look at the available traffic data, we expect
that the corridor can be split into two principal control areas. One that includes the
intersections from the northern project limits (Parkway and Denton Tap) through the Belt
Line / SH 114 interchange, and the other one that includes the intersections from Valley
View through the souther project limits (Belt Line and Oakdale). Due to the number of
signals in the southern section, it may be necessary to further subdivide it overlap the
sections in the analysis.
Discussion of the Number of Timing Plans Needed for the Corridor:
Based on the data already collected and the field observations, we expect that the northern
portion of the project will require AM and PM Peak Hour timing plans and an Off-Peak plan
that uses a shorter cycle length than the existing 80 second and 85 second plans. Although
this shorter cycle length may require that the controller be tolerant of coordination splits that
are shorter than the pedestrian crossing time requirements, it should be possible with the
existing controllers. This section appears to be highly directional and could therefore benefit
from weighted progression that would favor the southbound traffic in the AM Peak Hour and
the northbound direction in the PM Peak Hour.
For the southern control area we anticipate AM and PM Peak Hour timing plans, a Noon
Peak plan, an Off-Peak plan and a Saturday afternoon plan. The existing Off-Peak plan
appears to be functioning very well for the traffic during the weekday mid-afternoon. The
proposed Off-Peak Plan is expected to be similar to the existing plan, but modified to include
the additional signals on the north and south ends of the control area. Based on our field
observations, the PM Peak Hour plan could benefit from a slightly longer cycle length, and
an expanded use of lead-lag left-mm phasing. The mall entrance just north of SH 183 has
been striped off for a single left-mm lane due to the lack of an extra lane on the mall property
to .accept a dual left-mm lane~ We expect that operation at this intersection during peak
periods could be improved by servicing the northbound left-tm twice per cycle, both
leading and trailing.
Discu~i0n of Signal Phasing:
1. Lead-Lag Protected-Permissive Phasing for left turns ("Dallas Phasing"):
This would be a hard sell in Irving; the City of Irving would appreciate knowing
about any studies that have been done that show that "Dallas Phasing" is more
efficient as well as safer or just as safe as other phasing patterns.
Irving had 114 accidents related to permissive phasing last year.
Coppell's left-turn heads are a mixture of 4- and 5-section heads, without the
appropriate louvering and wiring needed to implement "Dallas Phasing."
Dallas County CMAQ Program
Project 75
February 18, 1997
Page 3
o
Left-turn lanes / Variable Lane Assignment:
· There is currently a Variable Lane Assignment condition at Denton Tap and
Parkway.
· Neither City expressed concems with recommendations related to Variable Lane
Assignment.
· The City of Coppell does not have any funding programmed for geometric or traffic
signal upgrade improvements.
· The City of Irving has considered and would like to receive any recommendations
related to the disallowing of left-roms at Country Club.
Set back loop detectors:
· Both Cities use these.
Vehicle Clearance Intervals:
· Both Cities agreed that these should be calculated rather than estimated.
All-red phases:
The City of Irving has no policy. They prefer to use 5 seconds of Yellow and not
over 2 seconds of All Red.
· The City of Coppell uses 1 to 1.5 seconds, but mostly 1.0 second.
Minimum Green:
· The City of Irving uses 6 seconds for left tums.
· The City of Coppell uses 5 to 6 seconds for left tums.
· ~ Both cities use 10.-5 to 12 seconds for throughs.
Night patterns:
· The City of Irving and the City of Coppell let the signals operate free at night.
· Mr. Tramel indicated that some of the previous studies had recommended the use of
a really short cycle length at night (=40 seconds) that was still coordinated.
· The cities expressed that they felt that the side street traffic at night was not heavy
enough to have a significant impact on the main street progression.
Dallas County CMAQ Program
Project 75
February 18, 1997
Page 4
Next Meeting:
The next meeting was set for:
March 18, 1997
2:00 PM - 3:00 PM
City of Irving
825 West Irving Boulevard
Transportation Department Conference Room
These minutes have been prepared by Jeremy Wyndham (214) 520-2116, and are considered
accurate unless the author is notified within 10 days of the preparation date.
Attachment: Sign-In Sheet
Distribute to:
All present
Ivan Nicodemus
Karen Jones
Don Cranford
Moosa Saghian
Gerry de Camp
File
DALLAS COUNTY
CMAQ PROGRAM
PROJECT REVIEW MEETING 1
SVERDRUP CIVIL, INC.
PROJECT #75
SIGN-IN SHEET
FEBRUARY 18, 1997
(- Tony Tramel DeShazo, Tang & Assoc. (214) 748-6740
Atul Patel City of Coppell (972) 304-3682
Jim Driscoll City of Irving (972) 721-2646
Kathy Mullins City of Irving (972)
721-2646
Mark Goode Inc. 520-2116
Sverdmp
(214)
/Jeremy Wyndham Sverdmp Civil, Inc. (214) 520-2116
Ivan Nicodemus Parsons Brinckerhoff (214) 747-6336 ext. 26
Karen Jones Parsons Brinekerhoff (214) 747-6336 ext. 25
Jim Bernier Parsons Brinckerhoff (214) 747-6336 ext. 31
James Allen ARS Engineers (214) 747-6336 ext. 30
Don Cranford Dallas County (214) 653-7151
Moosa Saghian TxDOT (214) 320-4435