SC-CFBISD-Riverchase-SY 990301 TRAFFIC STUDY
New elementary School
- For
Carrollton/Farmers Branch Independent School District
In
Coppell, Texas
Prepared for:
SHW Group Architects
Prepared by:
G.T.(Tom) Walton, P.E.
Consulting Traffic Engineer
March 1999
TABLE OF CONTENTS
THE SITE PLAN Page 1
- SITE CIRULATION Page 1
AREA ROADWAYS Page 2
SCHOOL SERVICE AREA Page 2
SCHOOL TRAFFIC DISTRIBUTION Page 2
_ EXISTING TRAFFIC VOLUMES Page 3
TRAFFIC IMPACT ON EXISTING ROADS Page 3
DEFINIOTIONS OF LOS Page 4
- SITE IMPACT ON ROADWAY LOS Page 5
EXISTING ROADWAY CONDITIONS Page 5
PROPOSED NEW ROADWAY Page 6
~ POTENTIAL SIGNALIZATION Page 6
CONCLUSIONS Page 7
RECOMMENDATIONS Page 8
THE SITE PLAN
The plan for the proposed elementary school shows it's location on the
northeast comer of the intersection of MacArthur Blvd and the eastward
_. extension of Starleaf St. The site has frontage on both MacArthur and the new
proposed street. All access to the site is on the south frontage along the
proposed street.
Four driveways are planned along the proposed street. For this study the drives
will be numbered 1-4 beginning with the drive closest to MacArthur and moving
-- east. The drives one and two serve the designated school bus drop-off and
pick-up area. They also provide access to a parking area with 32 ninety degree
parking spaces. The circulation aisle that connects the two drives is wide
enough for two lane operation. The aisle is bordered on the north and east
sides by a sidewalk which connects to the school building. Drive one is
approximately 120 feat east of MacArthur and drive two is approximately 200
-- feet further east. Driveway three is planned approximately 80 feet east of drive
two and drive four is approximately 200 feet east of three. Drives three and four
serve an area that has been planned for parent drop-off and pick-up. Another
- staff and visitor parking lot, providing 65 ninety degree parking spaces, is served
by the two eastern most driveways. An additional parking area is planned to the
east of the easternmost driveway at a future date.
SITE CIRCULATION:
According to information received from the transportation staff of the
_ CiFBISD, drives one and two will be used by the school buses serving the
school. Buses will approach the school eastbound from the MacArthur
intersection and turn left into drive number two. They will move in a one-way
- flow to the school to park on the north or east side of the aisle to discharge or
load students. Leaving the school the buses will exit onto the street from drive
one, turn right and proceed back to MacArthur..
Parents will approach the school eastbound from Mac, Arthur and turn left into
drive number four. They will move north to a point on the eastern or northern
- side of the aisle to drop off or pick up students. Leaving the school they will exit
onto the street from drive number three. They will turn right to return to
MacArthur Blvd. Service vehicles will enter the site by drive three to access the
- service area near the kitchen and dining room
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- MAJOR THOROUGHFARE PLAN
, CI T Y OF C OPPELL, TEXA$
-- AREA ROADWAYS:
The site for the proposed new elementary school is in the eastern part of
the City of Coppell. Traffic approaching the site must use either MacArhtur Blvd
from the north or south or Starleaf Street from the west.
- According to the City of Coppell Thoroughfare Plan, Mac, Arthur Blvd is
designated as a P6D, which means it is to be a 6 lane divided Principal arterial.
At the present time it is a four lane divided roadway. MacArthur Blvd is one of
the three north south princil~a~arterials serving the city. It is the only major
roadway in the eastern par~o~the city. It provides a link between the City of
_ Lewisville on the north and't~e City of Irving on the south.
Starleaf Drive is a two lane undivided roadway which extends west ~
_ its intersection with Mac, Arthur Blvd a short distance into the residential
development south of Sandy Lake Rd. Starleaf is one of only four accesses to
MacArthur from the large residential area to the west.
SCHOOL SERVICE AREA
-- Information received from the Carrollton I Farmers Branch staff indicates
that the new school is to serve students living south of Sandy Lake Road and
east of MacArthur Blvd. Some students will live in the area south of the Coppell
-' City Limits.
SCHOOL TRAFFIC DISTRIBUTION:
The .location of the new school in its service area indicates that traffic
_ approaching and leaving the site will be primarily from the south on Mac, Arthur
Blvd. For this study it will be assumed that 90% of the traffic will be from and to
the south and 10% from and to the north on Mac, Arthur. Based upon this
_ information, the primary offsite traffic movements that the school traffic will make
will be turning right from northbound on MacArthur to the site and turning left
from westbound 6n the new street serving the site to go south on Mac, Arthur. A
- small number of vehicles may turn left from southbound on MacArthur and turn
right from the site to go north on MacArthur. The traffic movements to be
expected by the site traffic both on and off site are shown on Figure 1.
-- 2
EXISTING TRAFFIC VOLUMES
-- In order to determine the volumes of traffic using MacArthur Blvd as it
passes the school site, 24-hour machine traffic counts were done during the
week of February 15-19, 1999. The counts were done on Tuesday and
-- Wednesday of the week to determine an average traffic volume situation.
Counts were done separately for each direction on MacArthur and also for each
direction on Starleaf west of MacArthur. The traffic count information will be
- used to evaluate the existing level of congestion on MacArthur Blvd and also to
evaluate whether the intersection of MacArthur and Starleaf meets the criteria for
_ a traffic signal. The count information is recorded in fifteen minute intervals and
subtotaled for each of the 24~ours of the day. The highest one hour volume
period is given for the AM and PM periods of the day. The results of the traffic
counts are given in the Appendix.
TRAFFIC IMPACT ON EXISTING ROADS
- In Order to evaluate the effect that the traffic generated by the new
elementary school will have on the surrounding area, a Traffic Impact Analysis
was completed. The methodology of the analysis involves an evaluation of the
- level'of service or level of congestion on the surrounding roadways under
existing'conditions, and then a similar evaluation with the traffic generated by
the school added to the system. The expected change in congestion determines
- the traffic impact of the new school.
Roadwav Capacity - The amount of traffic that a roadway is designed to
carry is a function of whether it is one-way or two-way, how many lanes it
has in each direction, if it is divided or undivided, how many driveways
_ are on it, the spacing and traffic control of intersections and the type of
area it serves. The roadways affected by the new school are MacArthur
~Blvd and Starleaf street. The capacities used in this analysis are 34,500
I:tr.~ip'~per day for Mac, Arthur Blvd, a 4 lane divided major
thoroughfare
000'- 10,000 ('~,per day for Starleaf Street, a 2 lane undivided
residential street.
Roadwav Level of Service - In order to determine how effectively the
roadway system is carrying traffic, a measure referred.to as the Level of
Service(LOS) has been developed. Level of Service is used to indicate
the effectiveness of operation of both intersections and roadway links.
- 3
For roadway link analysis, the level of service is a direct ratio of the links
traffic Volume to its capacity (v/c). The definitions of the various Levels of
Service fbr roadway links are given in the table below.
DEFINITIONS OF LEVELS OF SERVICE FOR ROADWAY SEGMENTS
Level of Service VIC Ratio Ranaes Descriotion
A < 0.35 Free Flow; Iow volumes
.- High speeds
B 0.35-0.49 Stable Flow;, operating
_ Speeds beginning to
Be restricted.
_ C 0.50-0.79 Stable flow; speeds and
Maneuverability controlled
By higher volumes.
D 0.80-0.89 Approaching unstable flow
With only tolerable operat-
-- lng speeds maintained.
E 0.90-1.00 Unstable flow; Iow operat-
- lng speeds with moment-
Ary stoppages.
-- F >1.00 Forced flow operation;
Low speeds with frequent
_ Stoppages for short or
Long periods of time.
Using the capacity volumes given above for the varioUs roadways and the
_ existing traffic volumes found in the APPENDIX, the current level of
service for Mac, Arthur Blvd, indicated by its vic ratio, is 19,061 ! 34,500 =
0.552, or LOS of C. The Level of Service for Starleaf street is 1,054 I
- 8,000 = 0.13 or LOS A. · t ~ h ~ J~C'rc .~.,r/,,~,"/
Site Traffic Generation - The amount of traffic that can be expected to be
generated by the proposed elementary school is calculated using trip
generation rates from the 1991 5th Edition of 'TRIP GENERATION'
published by the Institute of Transportation Engineers. The generation
rates are based upon the number of students attending the school.
Information received from the Carrolton ! Farmers Branch lSD staff
indicates that at the time the new school opens 540 students will be in
attendance. When the school reaches its planned capacity the student
-- population is expected to be 700.
At opening the school will generate 589 trips per day. During the AM
peak traffic hour the school will generate 162 trips. Of those trips 97 will
be inbound to the site and 65 will be outbound. When the school reaches
its capacity it will generate 763 trips per day. During the AM peak hour,
the school will generate 210 trips of which 126 will be inbound and 84 will
be outbound.
SITE IMPACT ON ROADWAY LOS
- Traffic generated by the new school will have to use MacArthur to
approach the site. Therefore the only roadway that will be affected by the
school will be Mac. Arthur Blvd. Adding the traffic generated by the school
-- to the measured volume on Mac, Arthur will give an indication of the impact
that the new school will have and traffic congestion on the subject section
of MacArthur. At opening of the school the new volume will be 19,650.
- Therefore the LOS will be increased to 19,650 ! 34,500 = 0.569 or LOS C.
EXISTING ROADWAY CONDITIONS
The site of the new school is on the east side of MacArthur Blvd betWeen Sandy
Lake Rd. on the north and Beltline Rd, on the south. MacArthur Blvd borders a
drainage area to the east and has alternating horizontal curves along its entire
length from Sandy Lake to Beltline. There is also some minor vertical curvature
_ through the area. The posted speed limit on Mac, Arthur is 35MPH. There is a
median opening on MacArthur at the Starleaf intersection that will provide
access to the school site. There is a left turn lane for southbound traffic with an
_ 80 foot storage length. There is a street turnout on the east side of MacArthur
opposite the median opening. Visibility to both the north and south is limited by
the horizontal and vertical curvature of Mac. Arthur. The available visibility from
- the east side of the intersection in both directions is approximately 400 feet.
PROPOSED NEW ROADWAY
The new roadway that will provide access to the new school will have to meet
City of Coppell thoroughfare standards. The road will serve the school and also
a small residential area planned to the south and east of the school. Therefore it
will function as a collector street and two way traffic flow will need to be
maintained at all times. The standards require that the roadway be between,.~2,, /
~and 40 feet wide. The si;,e of the road will be indicated by its traffic need_.~, it
,/~c~n be expected that during the peak school'frafrlc periods a large pO'~ion of th~
traffic will arrive and attempt to leave in a short time. Inbound traffic will create a
_.. large right turn demand on northbound Mac, Arthur. Outbound traffic will create~
large left turn demand from the new street to go south on Mac, Arthur. A lesser
J~ut still significant outbound right turn demand will also exist. These demands
indicate the need for separate right and left turn lanes for westbound traffic at
the intersection. To address these needs a three lane roadway, one lane-----...,.
eastbound and two lanes westbound, is indicated. In the area in front of the
school, the lSD staff indicated the need for on-street parking on the school
frontage between the driveways.
or "warranted' based upon the amount of traffic using the intersection. A
-- significan,.~mount of traffic must approach the intersection on both the main
street, t0,~his Yfase MacArthur, and on the side street, in this case Starleaf, during
each of e~g~llt'hours of an average day. Another concern is whether the
location of the proposed signal will allow traffic to move smoothly along
important arterials. The spacing between existing and proposed signals can
determine whether progressive traffic movement can be maintained along a
-- section of roadway. An equally important issue is the existence of a highly
hazardous situation that must be solved by the use of a traffic signal.
The traffic volumes measured as part of this study and included in the Appendix
indicate that the volumes on MacArthur Blvd will satisfy the criteria for a signal.
However the volumes approaching the intersection on Starleaf do not meet the
criteria for any hour of the day. Therefore a traffic signal cannot be warranted
based upon the volumes.
At the present time there are fully actuated traffic signals at the interSection of
-- 6
Mac, Arthur and Sandy Lake to the north of the site and at the intersection of
· MacArhtur and Beltline Rd. to the south. The distance between the two is
approximately one mile. The Starleaf intersection is approximately 113 of the y
way south of the Sandy Lake intersection. A desirable spacing between signals
for progressive movement is % to 113 of a mile. Therefore, a signal at the
Starleaf intersection would fit well into a future progressive system. .~,~,~ ~,~t, 54.
The triP generation analysis indicates that during the peak hour in the morning/
-- 65 vehicles Can be expected to leave the site when the school opens. Of that \~ .~'~ .X' ,~,v
number 60 Can be expected to turn left to go south nn M~c, Nlh,,r. The time at ~,c" %~,X ~'~.~'"~
which this traffic will be exiting tho school is fror~:30 to 8:30 ~r~.. This is tho W,~
'" same time as the highest southbound traffic flow of the day occurs on ' /~"'
Mac,N'thur. Over 1400 vehicles pass the site southbound during that time and/
over 200 vehicles pass northbound during the same time. Since the vehicles
turning left from the site must cross traffic in both directions nn Mac, Arthur, it will
be a very difficult and possibly hazardous maneuver/'~ will be even more' of ~
_ L-pT'~blem for the school busses that will all approach from and return to the south.~.-"
_ CONCLUSIONS:
The Site Plan - The layout and loCation of the separate school bus and parent
-- drop off and pick up areas w_ilLr, esult in little interaction between the different
sizes of vehicles. The few~ervicing the school will be able to flow
smoothly to the area nearest-[5'M-acArthur and back. The numerous private
- vehicles will move to the area' furthest from MacArthur and be able to queue in
the entire length of Starleaf along the school frontage if necessary. This will
eliminate the prob,,~t~ of a back-up onto Mac, Arthur. The site design provides
~ liberal aisle size, radt,[~ drop off area and parking.
Proposed road - A City of Coppell standard Collector street is to be built east of
Mac, Arthur Blvd to provide access to the new school. The necessary turning
movements, circulation, and needed~n street parkinct.~at both the intersection
and in front of the school Can be provided within the City of Coppell standard for
- Collector streets. '-~ I¥l- ~r~/ ~-?:~0~- ~.?0' ~:~'~
_ Traffic Impact - The amount of traffic created by the new school will have no
signifiCant impact on the level, of congestion which will remain at LOS C on
Intersection impact - The most signifiCant traffic impact of the new school will be
-- 7
at the Mac,Nthur I Starleaf intersection. Approximately 1/3 of the northbound'---~ ~ $ '~....~7~-
traffic on MacA/thur during the am peak hour will turn right into the new street. ~[t~'~'~'' '
The exiting traffic, both cars and buses, turning left onto MacArthur Blvd can
create serious operational problems at the intersection due to the high volume of
southbound traffic during the am peak period.
RECOMMENDATIONS:
1. A 40' radius should be provided for the west radius of drive number 1 to
ease the right turn of buses from the site to the street.
2. The roadway should be designed with a 38 - 40' width. This will provide"~
space for separate right and left turn lanes approaching the MacArthur
intersection along with an adequate eastbound traffic lane. In front of th' e
school, parking can be permitted on both sides of the street with adequate
space remaining for two way traffic. A suggested layout of the street is ~,4.~~,~
given in the Appendix.
3. A separate right turn lane with 100 to 200' of storage should be provided
for northbound traffic approaching the intersection. A 40' radius should be
designed for the right turn from Mac, Arthur to the east.
4. Even though a traffic signal cannot be warranted based on expected
traffic volumes, a signal should be considered based upon the need to
address the !eft turn traffic hazard..A detector actuated traffic signal at
the intersection can be design&d to operate efficiently in a progressive
system along MacArthur Blvd.
.,,~..~ -/&~'~ t~' ~ '""~.7'
8
APPENDIX
Na~Irthu~ Blvd
New lt~ht Turn Lane ,
Vol-me Cmmt Rel}ort
Generated by NSC3000 Version 2.021 Alpha(Nov 29 1995 08:54:16) Copyright 1990-1993 Mitron
Location .......... MacARTRIJR JUST NORT~ OF STARLEAF, SB
Location Code ..... 8
-- Jurisdiction ...... DALLAS
Recorder Set ...... 02/15/99 11:36
Recording Start ... 02/16/99 00:00
_ Recording End ..... 02/17/99 00:00
Sample Time ....... 15 Minutes
Operator Number ... 13
Machine Number .... 8
-- Channel ...........
Divide By ......... 2
Su,~%~tion ......... No
-- Two-Way ........... No
_ Tuesday 02/16/99 ~s--el: i Direction: S
0100 0200 0300 0400 0500 0600 0700 0800 OgO0 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 Totals
23 11 12 8 21 105 645 1424 1147 529 407 427 464 483 423 471 453 493 558 473 398 279 143 53 9450
8 3 5 3 I 7 55 355 373 193 94 89 108 129 102 101 125 111 149 138 90 88 58 23
5 2 0 2 3 16 108 345 329 138 BO 117 127 100 117 124 98 143 128 116 113 77 47 19
7 3 3 1 5 38 203 391 236 102 115 108 111 131 115 125 107 124 141 114 117 65 28 6
3 3 4 2 12 44 279 333 209 96 118 113 118 123 89 121 123 115 140 105 78 49 10 5
AM Peak Hour .................... 07:15 to 08:15 (1442 vehicles)
-- AM Peak Hour Factor ............. 92.2%
PM Peak Hour .................... 18:00 to 19:00 (558 vehicles)
PM Peak Hour Factor ............. 93.6%
Vol-me Co-nt Rg ort
Generated by HSC3000 Version 2.021 Alpha(Nov 29 1995 08:54:16) Copyright 1990-1993 Mitron
Location .......... MacARTHUR JUST SOUTH OF STARLEAF, NB
Location Code ..... 7
Jurisdiction ...... DALLAS
Recorder Set ...... 02/15/99 11:27
Recording Start ... 02/16/99 00:00
Recording End ..... 02/17/99 00:00
Sample Time ....... 15 Minutes
Operator Number ... 13
Machine Number .... 7
Channel ........... 1
Divide By ......... 2
Su,-~tion .......... No
Two-Way ........... No
Tuesday 02/16/99 Channel: i Direction: N
0100 0200 0300 0400 0500 0600 0700 0800 0900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 Total~
38 17 11 4 11 32 106 281 318 338 415 542 570 474 513 571 957 1570 1201 645 430 308 182 77 9611
10 5 4 0 3 6 16 55 76 96 99 105 165 118 136 131 190 375 340 225 129 94 69 18
12 5 4 2 I 9 22 71 78 79 83 125 139 105 123 130 215 415 344 169 115 88 49 13
-- 6 2 3 0 0 7 24 79 83 97 115 149 145 135 118 149 256 410 282 133 91 62 33 25
10 5 0 2 7 10 44 76 81 66 118 163 121 116 136 161 296 370 235 118 95 64 31 21
_ AM Peak Hour .................... 11:00 to 12:00 (542 vehicles)
AM Peak Hour Factor ............. 83.1%
PM Peak Hour .................... 17:00 to 18:00 (1570 vehicles)
PM Peak Hour Factor ............. 94.6%
Vol-me ~o-nt Rc~)o~
~nerated ~ ~C~00 Versi~ 2.021 Alpha(Nov 29 1995 0B:~:16) Copyright 1990-1993 Mitr0n
Location .......... STARLI~,F O-dST WBST OF MacAR~4-OR, BB
Location Code ..... 6
Jurisdiction ...... DALLAS
Recorder Set ...... 02/15/99 11:18
Recording Start ... 02/16/99 00:00
-- Recording End ..... 02/17/99 00:00
Sample Time ....... 15 Minutes
Operator Number ... 13
_ Machine Number .... 6
Channel ........... 1
Divide By ......... 2
Summation .......... No
-- Two-Way ........... No
-- Tuesday 02/16/99 ~a-~el: I Direction: E
0100 0200 0300 0400 0500 0600 0700 0800 0900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 Totals
2 0 3 2 4 15 39 69 42 29 19 21 36 28 31 24 28 35 33 33 11 12 10 5 531
0 0 0 0 0 I I 8 10 6 5 3 11 7 6 3 10 7 8 10 3 5 5 1
I 0 3 I 2 2 12 28 13 7 5 6 5 10 9 4 7 10 10 11 4 2 2 2
-- I 0 0 0 2 4 12 14 14 6 4 8 16 4 10 5 5 g 6 7 2 4 I 2
0 0 0 I 0 8 14 19 5 10 5 4 4 7 6 12 6 9 9 5 2 I 2 0
_ AM Pea~ Hour .................... 07:15 to 08:15 (71 vehicles)
AM Pea~ ttour Factor ............. 63.A%
PM Peak Hou~ .................... 12:30 to 13:30 (37 vehicles)
PM PeaJ~ Hou~ Factor ............. 57.8%
Vol-me Col~nt Repo~
Generated ~ ~C~O0 Version 2.021A]pha(Nov 29 1995 08:54:16) Co~r~ght 1990-1993 Mitron
Location .......... STARLEAF JUST WEST OF MacARTHUR, WB
Location Code ..... 5
Jurisdiction ...... DALLAS
Recorder Set ...... 02/15/99 11:09
Recording Start ... 02/16/99 00:00
Recording End ..... 02/17/99 00:00
Sample Time ....... 15 Minutes
Operator Number ... 13
Machine Number .... 5
Channel ........... 1
Divide By ......... 2
Su~c~,ation ....... -.. No
Two-Way ........... No
Tuesday 02/16/99 Channel: i Direction: W
0100 0200 0300 0400 0500 0600 0700 0800 0900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 Totals
4 0 5 I 1 3 6 12 13 18 13 19 29 27 22 40 50 70 63 49 28 23 21 6 523
I 0 2 0 ' 0 1 1 1 2 4 4 6 5 10 9 8 9 12 24 15 8 7 7 5
1 0 I 0 1 1 3 3 4 2 I 5 6 6 6 5 16 15 19 17 7 4 6 0
0 0 2 I 0 0 1 3 3 6 4 4 12 5 2 10 16 20 8 11 8 9 5 1
2 0 0 0 0 1 1 5 4 6 4 4 6 6 5 17 9 23 12 6 5 3 3 0
AM Peak Hour .................... 10:30 to 11:30 (19 vehicles)
AM Peak Hour Factor ............. 79.2%
PM Peak Hour .................... 17:30 to 18:30 (86 vehicles)
PM Peak Hour Factor ............. 89.6%