HomeMy WebLinkAboutLITTLE CAESARS PUD PRELIMINARY - 28 92 - SUBMITTAL DOCUMENTS - ROUND 1 - TRAFFIC STUDY (3)i
LITTLE CAESARS PIZZA
SITE ACCESS STUDY
FORT COLLINS, COLORADO
MAY 1992
Prepared for:
Little Caesars Pizza of Northern Colorado, Inc.
Shores Six, Suite 102
Fort Collins, Colorado 80525
N
Prepared by:
MATTHEW J. DELICH, P.E.
3413 Banyan Avenue
Loveland, Colorado 80538
Phone (303) 669-2061
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TRIP DISTRIBUTION Figure 4
tShort-Terrr✓Long-Term
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Trip Assignment
Trip assignment is how the generated and distributed trips
are expected to be loaded on the street system. The assigned
trips are the result of the trip distribution process.
Figures 5 and 6 show the noon and afternoon peak hour
assignments of the Little Caesars generated traffic with the
background traffic in the area for the short and long range
levels of development. The traffic assignment shown in Figures
5 and 6 is considered to be conservative, in that all traffic is
concentrated on Mitchell Drive. There are two other accesses
available: one to Horsetooth Road via the existing access to the
west of the office/bank complex, and the other to JFK parkway via
the existing access to the south of the office/bank complex.
signal Warrants
As a matter of policy, traffic signals are not installed at
any location unless warrants are met according to the Manual on
Uniform Traffic Control Devices. However, it is possible to
determine whether traffic signal warrants are likely to be met
based upon estimated Average Daily Traffic (ADT) and utilizing
the charts shown in Appendix E. Using the traffic volumes shown
in Figures 5 and 6, traffic signal warrants will not be met at
the intersection of Mitchell Drive and Horsetooth Road. This
report assumes no change in traffic control devices.
11
1
SHORT-TERM PEAK HOUR TRAFFIC Figure 5
' Noon/PM Peak Hour
LO
10/50
I �-- 1025/1675
f 75/100
75/50 1
975/1175 --- I I
75/100
n o LO
co
r�
r N
N A
r M 33/52
2/3
PlAr
w
0
J
w
2
U
H
4
N
HORSETOOTH ROAD
LONG-TERM PEAK HOUR TRAFFIC Figure 6
NoorVPM Peak Hour
I
Operations Analysis
Capacity analysis was
performed on
the intersection of
Mitchell Drive and Horsetooth
Road adjacent
to Little Caesars for
the short range and long
capacity analyses are summarized
range levels
in Tables
of development. The
3 and 4. Calculation
forms for these analyses are
provided in Appendix F.
Using the peak hour traffic volumes shown in Figure 5, the
Horsetooth/Mitchell intersection operation will be acceptable
considering the recent research cited earlier. While there will
be some
delays
to straight and left turn exits from Mitchell
'
Drive and The
Square, these movements should be allowed to
continue
until
operational problems arise. The operational
problems
will
not likely occur until after Mitchell Drive is
'
extended
to Bockman
Drive.
Using the peak hour traffic volumes shown in Figure 6, the
' Horsetooth/Mitchell intersection operation will be acceptable,
except for the straight/left turn exits from Mitchell Drive and
The Square. Delays will increase for the eastbound and westbound
' left turns on Horsetooth Road at this intersection. The delays
to the straight and left turn exits is not of concern, since this
type of operation occurs throughout the City and is generally
accepted. Of concern is the length of the double left -turn lanes
on Horsetooth Road approaching College Avenue. Based on the Year
2010 traffic projections, the needed length of these westbound
left turn lanes will not allow for the use of an eastbound left
turn lane into The Square. However, without a channelization
median to physically eliminate the selected movements, all turns
can be made at the Mitchell intersection. Construction of a
' channelization median would also eliminate the northbound and
southbound straight and left turn exits at this intersection. If
the City of Fort Collins chooses to construct this median, it is
' recommended that the median be designed to allow the westbound
left turns from Horsetooth Road to Mitchell Drive. This design
is geometrically feasible. By allowing the westbound left turns,
Mitchell Drive can better function as a recirculation street for
the southeast corner of the College/Horsetooth intersection.
The design of Mitchell Drive can accommmodate a relatively
' short left turn lane for traffic entering Little Caesars via
southbound Mitchell Drive. A 30-foot left turn lane plus 60-foot
taper can be povided on Mitchell Drive. This left turn storage
' will be adequate for the inbound traffic since the the opposing
nortbound traffic on Mitchell Drive will be low. The access
point should operate at Level of Service A with no delays for
southbound left turns.
1
Accident Analysis
' As traffic increases in this area, the number of traffic
accidents will likely increase. Although long delays do not
directly relate to a higher accident rate, increased accidents
1
14
can occur at full movement unsignalized intersections. If an
' unusually high accident rate is noted at this intersection in the
future, it would be advisable to restrict left turns out of the
site. Such a turn restriction is not called for in the short
' term, and may never be needed. The recommended control devices
and geometrics should minimize vehicular conflicts and maximize
vehicular separation. Therefore, the accident rate should be at
its minimum for a typical urban condition.
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15
Intersection
Table 3
Short Range (1993) Peak Hour Operation
Operation
NOON PM
Horsetooth Rd/Mitchell Dr
EB L A C
WB L A A
NB L/T E (D) E (D)
NB R A A
SB L/T E (C/D) E (D)
SB R A A
(-) Level of Service based on delay criteria
Table 4
Long Range (2010) Peak Hour Operation
Intersection
Horsetooth Rd/Mitchell Dr
Operation
NOON PM
EB
L
C
E
WB
L
C
D
NB
L/T
F (D/E)
F (E)
NB
R
A
B
SB
L/T
F (D)
F (D/E)
SB
R
A
C
(-)
Level of Service based on delay criteria
16
IV. CONCLUSIONS
' This study assessed the impacts of Little Caesars on the
existing (short range - 1993) and future (long range - 2010)
' street system in the vicinity of the proposed development. As a
result of this analysis, the following is concluded:
- The development of Little Caesars is feasible from a
traffic engineering standpoint. At full development as proposed,
approximately 70 noon and 110 PM peak hour trip ends will be
generated at this site.
- Current operations at the stop sign controlled
Horsetooth/The Square intersection are acceptable.
' - No new signalized intersections will be warranted as a
result of this development. The intersection of Horsetooth Road
and Mitchell Drive will function adequately in the future with
this development. Left turns out onto Horsetooth Road may face
some long delays during peak hours of operation, but this condi-
tion does not warrant signalization.
' - Due to the potential length of the westbound left turn
lanes at the College/Horsetooth'intersection, there may be a need
' to eliminate the eastbound left turns into The Square. The
westbound left turns into Mitchell Drive should be accommodated
by any future median design.
' - A short left turn lane can be provided for southbound
ll MitcheDrive at the Little Caesars access. This left turn lane
will provide adequate storage for southbound left turns wishing
' to enter the site.
- With proper traffic control and geometrics, the accident
rate should be minimal for an urban condition.
J
17
A P P E N D I X A
IV#ATTHEW J. DEL ICH, P.E.
3413 BANYAN AVENUE
LOVELAND, CO 80538
TABULAR SUMMARY OF VEHICLE COUNTS
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EXECUTIVE SUMMARY
Little Caesars Pizza of Northern Colorado, Inc. is proposing
to construct a 2,300 square -foot restaurant and a related 1,800
' square -foot office building at the southeast corner of Horsetooth
Road and Mitchell Drive (future) in Fort Collins, Colorado. This
traffic impact study involved the steps of trip generation, trip
distribution, trip assignment, capacity analysis, traffic signal
' warrant analysis, and accident analysis.
This study assessed the impacts of Little Caesars on the
' existing (short range - 1993) and future (long range - 2010)
street system in the vicinity of the proposed development. As a
result of this analysis, the following is concluded:
' - The development of Little Caesars is feasible from a
traffic engineering standpoint. At full development as proposed,
approximately 70 noon and 110 PM peak hour trip ends will be
generated at this site.
- Current operations at the stop sign controlled
Horsetooth/The Square intersection are acceptable.
No new signalized intersections will be warranted as a
result of this development. The intersection of Horsetooth Road
and Mitchell Drive will function adequately in the future with
this development. Left turns out onto Horsetooth Road may face
some long delays during peak hours of operation, but this condi-
tion does not warrant signalization.
- Due to the potential length of the westbound left turn
lanes at the College/Horsetooth intersection, there may be a need
to eliminate the eastbound left turns into The Square. The
westbound left turns into Mitchell Drive should be accommodated
' by any future median design.
A short left turn lane can be provided for southbound
Mitchell Drive at the Little Caesars access. This left turn lane
will provide adequate storage for southbound left turns wishing
to enter the site.
- With proper traffic control and geometrics, the accident
rate should be minimal for -an urban condition.
11
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2
Site Code : 00000001
N-S Street: COLLEGE AVE.
E-R Street: HORSETOOTH RD.
SUNNY
CITY OF FORT COLLINS
Movements hy: Primary
PEAK PERIOD ANALYSIS FOR THE PERIOD: 12:00 PM - 01:00 ?1
DIRECTION
START
PEAK HR
..CLUMEE ...........
...... PERCENTS
.......
FP.OM
PEAK HOUR
FACTOR
PEDS Right
Thru
Left
— ------------------------
Tots!
—
PEDS R!nht Thru Left
—— -
-----------------------------------------------
North
12:00 PN
0.5B
0 154
1123
1396
0 11
?!
a
East
12:00 PN
0. BE
I !la
301
2S2
697
0 16
43
40
Scut}.
12:00 P1
0.?l
. 194
068
193
'.755
0 14
71
!4
Rest
.[:00 PM
0.31
,. 20c
347
27i
779'
0 26
;4
:.
Entire
intersea5an
North
12:00 ?M
0.92
0 154
1123
ii-
i390
.. !!
EI
B
East
O.SB
! !i4
301
232
6?7
0 16
4Z
40
South
0.91
194
960
t?3
13S`_
0 is
71
!4
most
0.31
7 206
343
220
779
D 26
44
70
COLLEGE
AVE.
.
iV
.............
S
,..
1312
....
[PEDS
1 0
! 154
11123 1113
1.............
1 CFEDS 3
..................
..................
___
1390 ____
__
114
..........
..................
648
1
1 __________—_
... HORSETOOTH RD.
--------------
697
301
PASS: 1
FILE: 01-9-89
DATE: 9!21/9c
------------ __________________
230 __ __ 282
343 779 HORSETOCTH RD. ...
______________
650 ..........
206 __ ___ 1355 ____ ..................
..................
____________x ___________________
[PEDS 3 : 197, 968 194 _ [PEDS 7
. 1611
COLLEGE AVE.
CITY OF F]RT COLL!NS
Ste Code : 00000001 PAGE: I
N-S Street: CCLLE-E AVE. FILE: 01-9-89
E-R Street: HORSETOOTH RD.
SUNNY Movements by: Primary DATE: 9Y21??9
PEA!: PERIOD ANALYSIS FOR THE PERIOD: 04:30 PM - 05:70 P4
OIAE.CT!O.N START PEAK HR ........... VOLOMES ........... ...... mrarENTS .......
FROM PEAK HOUR FACTOR PEOC Riaht TNru Left %tal FE^-S Rich: Thru Leit
------- --__--__—----- —_____—------ —------ -- --- —__--____—_--
North 4:70 PM. 0.90 ! 111 !e89 !3! 1797 ; ) 1. ^ ;;__
East 4:30 Ph 0.2G .__ Seri 26E 1015 0 15 59 [6
South 4:D PM 0.97 1 216 :!1? 225 1624 I7 69 IS
Rest 4:b0 PM 0.99 1 22't 43E 2'S 57m 0 25 50 _71
.
Fear !ntersect!.n
north 4:30 P'. 0.59 ! !75 1498 !',1 !; 9i ^, 10 3 7
Gast 0. Sy ! L2 :00 ?63 !05 .0 15 3? 26
:ouch 0.97 ?16 !lio 239 6524 0 13 69 1G
Yest 0.99 1 222 439 219 B?9 0
COLLEGE AVE. N
S
1.. 1490 ...
C PEDS 3 1 ! 179 1148E 1131 1............1 1 [PEDS 3
__________________* y.______—___________
................
.. ___ 1797 ____ __ 152
.......... 1067
.................. __________________
... HORSETOOTH RD. 1015 600
--------------
__________________ __________________
219 -- -- 263
438 879 HORSETOOTH RD. ...
--------------
785 ..........
222 __ ___ 1624 ____ .................
..................
------------------ .r__—______—________
CPEDS 3 1 289 :1119 216 1 CPEDS 7
1973 ...
...1 COLLEGE AVE.
------------
m = m m ! =
CITY OF FORT COLLINS
site Code : 0000010,
PAGE: 1
N-S Street: J.F.K. PARKWAY
FILE: 102-1091
r_W Street: RORSETD.OTH RD.
SUNNY : SUNNY
Movements by: Primary.
DATE: 101087P1
PEAK PERIOD ANALYSIS FOR THE PERIOD: 12:C0
Ph - 01:D0
PM
DIRECTION START
PEAK uo
........... .MLUMES ...........
...... PERCENTS .......
FROM PEAK HOUR
FACTOR
PED Right Thru Left
Total
PED Right Thr_ Left
Nort.^. ...00 FM
0.84
: 03 _.
IQ
70 26
East !2:00 PM
0.96
i 51 101 20
572
0 c AR -
autl .2:00 PM
0.77
_ .. 11 45
: ^_! :5 is
West 12:00 PM
0.79
4 !9 627 lei
748
i 84 14
Entire !..trsect:va
North 12: C0 PM
0.94
,. 103 7 39
!43
2 70 _ 2i
East
0.26
5l to! -.
E72
1)8 99
South
^..77
2 15 11 45
7!
- ?! ._ 6:
West
0.73
4 19 62? i0:
748
! ^ '24 14
J. F.K. PARTWAY
.' .... N
______________
..
1..
165
..
....
C PED J z:
------------------
107
I 7 28 1............t
I CFED J
.a____________—__—__
...................
..................
---
148 ----
__ 51
.......... 745
..................
1 __________________
... HORSETOOTH RD.
--------------
672 601
------------------
10_
__
__ 20
627
746
HORSETOOTH RD. ...
--------------
__________________
_
:..680 ..........
18
--
---
71 ----
..................
. . . . . . . . . . . . . . . . . .
____•
—__—_—[FED J 4
1........
.... 45 I
11
r__________________
15 I 2: CF•ED
....
45 ...,
.....
J.F.K. PARIOWAY
-------------
CITY OF FORT COLLINS
.its Code : 00000103 PAGE: I
N-S Street: J.F.K. PARCNAY FILE: 103-1091
E-W Street: HOREETOOTH RD.
SUNNY : SUNNY Moveserts by: Pr aar7 DATE: 101091?1
PEAK PERIOD ANALYSIS FOR THE PERIOD: 04:30 PR - 05::0 P1
IT: rrT. START REM HR ........... VOLUMES ........... ...... PERCENTS .......
FROM PEAK H0U9 FACTOR REn Right Thru Left Total. PED P.igNt Thru Left
----- — --- — ------ _____—_____________—_
North {::0 FM 0.70 114 5 57 '7= 65 3 v2
East 4::0 PM 0.00 { 4. . is MI U 94
SOutt. 4::0 PM 0.75 1 !2 7 32 5! p !4 63
West 4::0 PM 0.87 4 ii S21 RR Ric A
Eut!re Iotersect:o.^.
Math 4:30 PM 0.70 '. 114 - 65 ._
East 0.90 4 47 961 .- M! 0 5 94 1
South 0.75 1 12 . -_ .! _ 24 !; E3
West 0.99 4 I6 924 9? ?3? 'I ? E9 it
J. F. 1:. F•AFJ'WAY _ IV
S
..... 15 ....
CFED J I 1114 1 5 1 57 4 CFED J
____________________________________
..................
. ............... 176 ---- __ 47
. ......... 1107
------------------
... HORSETOOTH RD. 1021 961
______________
--
99 -- -- 17
824 9=9 HORSETOOTH RD. ...
--------------
993 ..........
16 __ ___ 57 ____ ..................
..................
__________________ ..__—___--__________
CFED J 4 .............1 32 7 1 12 1 CFED 3
.. :54
J. F. I:. PARKWAY
A P P E N D I X B
1985 HCM: UNSIGNALIZED INTERSECTIONS -
Page-1
xxtzx��x�xxx:rxxx:�*x**:��xx*zxs***xxx***x*x*xx��xx*xxxxx�:x*�xxx��x x.
IDENTIFYING INFORMATION
---------------------------------------------------------------------
AVERAGE RUNNING SPEED, MAJOR STREET ..............
40
PEAK HOUR FACTOR .................................
1
AREA POPULATION ..................................
100000
NAME OF THE EAST/WEST STREET .....................
Horsetooth Road
NAME OF THE NORTH/SOUTH STREET ...................
The Square
NAME OF THE ANALYST ..............................
klk
DATE OF THE ANALYSIS (mm/dd/yy)..................
5/6/92
TIME PERIOD ANALYZED .............................
noon
OTHER INFORMATION: Recent Traffic Count
INTERSECTION TYPE AND CONTROL
---------------------------------------------------------------------
INTERSECTION TYPE: T-INTERSECTION
MAJOR STREET DIRECTION: EAST/WEST
CONTROL TYPE SOUTHBOUND: STOP SIGN
TRAFFIC VOLUMES
---------------------------------------------------------------------
EB WB NB SB
LEFT 45 0 -- 7
THRU 633 673 -- 0
RIGHT 0 9 -- 36
NUMBER OF LANES
---------------------------------------------------------------------
EB WB NB SB
----------------------------
LANES 2 2 -- 2
CAPACITY AND LEVEL -OF -SERVICE Page-3
---------------------------------------------------------------------
POTEN- ACTUAL
FLOW- TIAL MOVEMENT SHARED RESERVE
RATE CAPACITY CAPACITY CAPACITY CAPACITY
MOVEMENT v(pcph) c (pcph) c (pcph) c (pcph) c = c - v LOS
P M SH R SH
------------------------------------------------ ---
MINOR STREET
SB LEFT 8 88 83 83 75 E
RIGHT 40 673 673 673 634 A
MAJOR STREET
EB LEFT 50 502 502 502 452 A
1985 HCM: UNSIGNALIZED INTERSECTIONS Page-1
�xtYt�t��Y*xrx�%Y���xxtxYtx�tt*t�*�xrstt*�t�iY#**kti**YZX�x1*�*X�xxtW
IDENTIFYING INFORMATION
AVERAGE RUNNING SPEED, MAJOR STREET ..............
40
PEAK HOUR FACTOR .................................
1
AREA POPULATION ..................................
100000
NAME OF THE EAST/WEST STREET .....................
Horsetooth Road
NAME OF THE NORTH/SOUTH STREET ...................
The Sauare
NAME OF THE ANALYST ..............................
klk
DATE OF THE ANALYSIS (mm/dd/yy)..................
5/6/92
TIME PERIOD ANALYZED .............................
PM Peak Hour
OTHER INFORMATION: Recent Traffic Count
INTERSECTION TYPE AND CONTROL
---------------------------------------------------------------------
INTERSECTION TYPE: T-INTERSECTION
MAJOR STREET DIRECTION: EAST/WEST
CONTROL TYPE SOUTHBOUND: STOP SIGN
TRAFFIC VOLUMES
---------------
EB WB NB SB
---- ---- ---- ----
LEFT 31 0 -- 6
THRU 763 1083 -- 0
RIGHT 0 28 -- 47
NUMBER OF LANES
-------------------------------------------------
ES WB NB SB
----------------------------
LANES 2 2 -- 2
CAPACITY AND LEVEL -OF -SERVICE
Page-3
-------------------------------------------------------
POTEN- ACTUAL
FLOW- TIAL MOVEMENT SHARED RESERVE
RATE CAPACITY CAPACITY CAPACITY CAPACITY
MOVEMENT v(Pcph) c (Pcph) c (Pcph) c (Pcph) c = c - v LOS
P M SH R SH
------------------------------------------------ ---
MINOR STREET
SB LEFT 7 60 56 56 49 E
RIGHT 52 511 511 511 459 A
MAJOR STREET
EB LEFT 34 288 288 288 254 C
A P P E N D I X C
LE -Al VIA IJE V J, E 9(2I.1 ER I A
H)u
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Levtal-oI--sm-vir_r rr-It.tt-Ia for ullsiolio!i^nd i►ILerser_-
tiolls ar ra stal:r(1 ill very tlelleral ter-nls, alld Ire related
to tlr:.11rr-nl delay r-anur.'s /tllalyr-is for a stop- or-
yirld-r-twiltrollyd illl:ertirrl:lrlt► results ill soluLiol►s lot -
tilt:? tallaci Ly tit each 1 airs oil the nlirlol- approaches. 'I he
1evt=1-of --srr"vIC-e r-r-ittar-In at-e then baser! on tilt-
1 esrr-Vr. C11'" 1_IIICit rd, tapari ty or tilt_ I Ellie ill t4ut-stioll,
t-st1)ressell ill passr-nyer- cars per (tour lF'Cr'lll.
RE5LItvr 1:0,101CIIY LLVrA. t)1" EXFECIEU UELOY IU
11'L'I"'II1 St-AWIUE HIWUR 5II2EET 11'Mr-FIC
Little or llo delay
Sht.-wt trar tic delays
fiver -ant, tr'a r f i c delays
Lolly Ernt f i c delays
Very lolls trarfic delays
WHIt'll dr,111 nd volrunc r_ncr.rtln tilt, tapclty or the latle,
e;I L-reimi dr_l rlys will hi! r:tlrt.lt_niter etl with (1ueui r►y wlli th
Illny r.rltInI? srvr..rt+ tt.nlowititin ariertiny other- trarfJc
movnmclltti tit tilt? Itlr.rrtvvi:lt/1). this tvilditirrl usually
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INTIAIN_IOt_ ►NTAIN SI (TR)N
OOISE, IDAllO JULY 15-18, 1990
1
� Compendium of
� Technical Papers
I
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1
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I Institute Of Transportation Engineers
a
43rd Annual Meeting
Boise, Idaho
July 15-18, 1990
11
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Intersection Delay At Unsignalized Intersections
Matthew J. Delich, P.E.
Private Consultant
Loveland. Colorado
AIISTRACT
The technique described in the Ifi6way
Capacity Manual, Special Report 209, Chapter
10, Unsignalized Intersections relates a c:dct-
lated reserve capacity to level of service to it
very unspecific description of expected delay.
The signalized intersection technique in the
Highway Capacity Manual relates level of
service to a range of stopped delay per vehicle.
It would seem to be consistent to relate level
of scrvice at an unsignalized intersection [u it
range of actual delay per approach vehicle.
This research provides some limited data on
intersection delay related to the calculated
reserve capacity at selected T-intersections. At
the time traffic volumes were colicaed, inter-
section delays were also obtained for selected
movements. The intersection delay technique
is described in the Manual of Traffic Engineer -
in Studies, I FE, 1976, Chapter 8. By compar-
ing the calculated reserve capacity using the
counted traffic volumes to the observed aver-
age delay per approach vehicle, a table of
delays per approach vehicle could be deter-
mined. This, in urn, could be plotted to
determine a range of delay given a calculated
level of service.
INTRODUCTION
The means of evaluating the operation at an
unsignalized intersection is by determining the
level of service. The procedure ill the 1985
Hiehwav Capacity Manual (IICM) is primarily
145
taken front a German document (reference 1),
which uses gaps in the major Irafftc stream
t lilized by vehicles trussing or turning through
that slreanr.
In the IICM, the level of scrvice is related in
vehicle delay. This is cstccially true in the
evaluation al it signalized intersection. 1luwev-
er, in llte case of all unsignalized intersection,
level of scrvice is rclnlcd lu it nebulous mea-
sure of delay this[ call man different things to
different people.
RESEARCH OII.IECTIVES
This research was undertaken to relate level of
service to a definitive range of vehicle (]clay
for the minor street traffic now. The objec-
tives of the research were:
Compare the level of service (reserve
capacity) to a range of vehicle delay, in
seconds, for the stopped traffic on the
minor street.
Determine a curve which best dc-
scribes that range of vehicle delay.
RESltWII APPROACH AND LIMITA-
TIONS
Traffic counts were conducted al a number of
stop sign controlled iutcisccions in port
Collins, Colorado cud Cheyenne, Wyoming.
These volumes were used Ill determine reserve
capacity in passenger curs per hour (peph)
Intersection Delay At Unsignalized Intersections
according to procedures documented in the
IICM. Highway capacity softw:ne developed
by the Federal I lighway Administration, U.S.-
D.O.T. was used to perform these calculations.
Along with the traffic volumes, vehicle delay
was measure(] for each applonch vehicle
according to pntccdures described in Chapter
8, "Intersection Dclays; Manual of Trallie
EI1L'inccring Slgdirx.
Due to cllmrges in critical gap sire (lite In
speed, number of Inurs on the major strrd,
and nundxr of ]cgs ill the inlerserliun, onby'l'-
inlcisections were evaluated. 14nthcr, in all
cases, the major sheet was live lanes (4
through lanes and nuc left -loin Inue) and the
speed limit on the major meet was 35 mph.
INTERSF,('HON I*3 AY STUDY
At the time traffic volumes were obtained at
each of the intersections, traffic delays were
also obtained for Moth right- and left -turning
vehicles from the minor street. The methodol-
ogy used was n procedure which involved
counting the number of vehicles occupying an
intersection approach (right- or left -turn lanes
constitute two approaches) at successive time
intervals for the observation period. The
successive time interval selected was every 15
seconds. Each successive count represented
an instantaneous density or number of vehicles
occupying the intersection approach per time
interval. These counts were accompanied by
total volume counts of each approach. The
average delay per vehicle in each approach can
be expressed by:
D = Ni/V
where:
1) = Average delay tar nppmarh vehicle
N = Total deusily room, or thv sum of vchi-
cics obscivcd during the llctimlic density
counts each t secuuds
t = 'I irate intervals between density obscrva-
lions (15 seconds)
146
V = Total volume entering [he ap-
proach during the study period.
A total of 61 fifteen minute observations wets
conducted. The average delay per approach
vehicle for troth right and left turns for each
observation was tabulated. The calculated
delays were rounded to the nearest whole
second. The calculated delay per approach
vehicle for right turns ranged from 2 seconds
io 29 seconds. The mean was calculated at 9.9
seconds. The calculated delay per approach
vehicle for left turns ranged from 6 seconds to
105 seconds. The mean was calculated at 27.0
seconds.
LINEL OF SERVICE CALCULATION
Using the same 15 minute periods from the
intersection delay study portion of this re-
search, level of scrvice calculations were per-
formed. Since the level of service calculation
requires hourly traffic, the volumes for each 15
minute period was factored by four. This not
only gives an hourly volume, but also assumes
a peak hour factor of 1.0.
Reserve capacity in passenger cars per hour
(peph) was tabulated for the right turns and
left turns for each observation. The calculated
reserve capacities ranged from 36 to 882 peph
for the right turns. The mean was calculated
at 5655 peph. Most of the calculated levels of
service were in the A category (> 4fif) peph).
The calculated reserve capacities ranged from -
75 to 241 peph for [he left turns. The mean
was calculated tit 60.9 peph. Most of the
calculated levels of service were in the D
category (I(al-2(NI peph), E category (04W
peph), and F category (< 0 peph).
ANALYSIS
Using the output data dor right turns and left
turns from the delay study and the capacity
study, each corresponding observation point
was plotted and least squares graphical analysis
was performed.
1
I. INTRODUCTION
This site access study addresses the capacity, geometric,
and control requirements at and near a proposed Little Caesars
' Pizza Restaurant known hereinafter as Little Caesars. It is
located at the southeast corner of Horsetooth Road and future
Mitchell Drive in Fort Collins, Colorado. This study addresses
the traffic impacts at two levels of development: 1) a short
range future (1993), and 2) a long range future (2010).
During the course of the analysis, numerous contacts were
made with the project planning consultant (Architecture One), the
developer (Little Caesars), and the Fort Collins Traffic
Engineering Department. This study conforms to the format set
' forth in the Fort Collins Traffic Impact Study Guidelines. The
study involved the following steps:
- Collect physical, traffic and development data.
- Perform trip generation, trip distribution, and trip
assignment.
- Determine peak hour traffic volumes.
- Conduct capacity and operational level of service
analyses on key intersections.
Analyze signal warrants.
- Analyze potential changes in accidents and safety
considerations.
II. EXISTING CONDITIONS
The location of Little Caesars is shown in Figure 1. Since
' the impact in the short range, as well as the long range, is of
concern, it is important that a thorough understanding of the
existing conditions be presented.
Land Use
The proposed site for little Caesars is located in an area
of south Fort Collins which is, for the most part, developed. To
the north of the site is a retail shopping center known as The
' Square. East of the site is a bank/office building. The
southeast corner of Horsetooth Road and College Avenue (due west
of the site) is vacant. To the south of the site are various
retail businesses along the east side of College Avenue,
including a hardware store, florist, fast food restaurant, auto
parts store, and a toy store.
1
3
= M � 9"
Figure 1 shows the plot of calculated reserve
capacity versus calculated delay per approach
vehicle for the right turns. The results of the
graphical analysis arc also plotted. By calculat-
ing confidence interval as a range of delay per
approach for each calculated reserve capacity,
a reasonable prediction of delay can be made.
For example, a calculated reserve capacity of
400 pcph would yield a delay per right -turn
approach vehicle of 10-15
seconds.
Figure 2 shows the plot of calculated reserve
capacity versus calculated delay per approach
vehicle for left turns. The results of the
graphical analysis are also plotted. Using the
confidence interval, a prediction of the range
of delay can be made. Ilowever, the data for
the left turns is all in the -1(x) to +200 range
of values. Therefore, the delay for left turns
is only valid for reserve capacilitx at the lower
end of the scale using the data considered in
this study. For example, a calculated reserve
capacity of 100 pcph would yield a delay per
left -turn approach vehicle of 12-22 scainds.
The sin: of this range indicates that more data
is needed to reduce the prediction range.
CONCLUSIONS
Given The limited data obtained (61 observa-
tions), it appears as though the methodology
can give a reasonable indication of the range
of delay for vehicles entering a street at a stop
sign controlled T-intersection. However, more
data is needed to fill in gaps:
Data is needed at intersection where
the right turns operate at levels of
service B, C, D, E.
Data is needed at intersections where
the left turns operalc at levels of ser-
vice A, B, C.
•s r M M M M
District 6 1990 Annual Meeting
close as 1/4 mile away. There was no signal
pnogrusion pattern on the major street.
lluwever, it was noticed that both operation
and delay were influenced by vehicle queues
created by the signals on the main street. This
was not accounted for in any of the calcula-
tions or analyses. An cfiint should be made to
select intersections which are not affected by
main street signals.
'Ihe statistical analysis on this dale and addi.
tional data should be much more rigorous than
that used in this analysis. The curve devel-
oped using nil the data should be malheaali-
c:dly derived and adequately tested ;sing
accepted slalislical pracliccs.
The data presented is only for it T-intersection
with a four -late (plus Icfl-turn lane) main
street with At Ix)slcd slx:ed of 35 mph. Dana
should also be collected lit it number of main
sheet posted speeds (45 utph and 55 mph).
Data should also be collected for a T-imersec-
tion on u lwt)lane sheet at various Ix)iled
speed limits.
11' the additional data unit analysts for a T-
intersection point toward the validity of this
approach, then similar data should
Ix; collected and analyses performed at four -
leg intersections.
BIBLIOGRAPHY
❑ )x, Paul D. and Joseph C. Oppcnl:mder,
HAD. Manual of Traffic I'.ngincerine Studies
4111 Fdilion. Arlington, Virginia: Institute of
Transportation L-nginecls, 1970, Pgs. I(N)-I 12.
Itoess, Roger P. et al. llighw;aCltlmcily
Manual, Special Re1xm1 2119. Washinglon,
D.C.: TmtsslxnTatun Rcsc;uch Ihnrrd, 1985,
Chapter 10.,
M" M s M M M M
Intersection Delay At Unsignalized Intersections
fur Alms Strmxcenwcsen, Koln, Germany (1972).
At a number of the analyaod iniencetiuts, REFERENCE'
there were signals upstream from the analyzed I. 'Met kbadl for Lichlsiguahudage) an I mud- -
intera;ctions. Some of thus signals were as strassen Ausgabc 1972", futschungsgescllschnll 149
147
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Intersection Delay At Unslgnallzed Intersections
District 6 1000 Annual Meeting
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RESERVE CAPACITY (peph) yip
RESERVE CAPACITY (peph)
COMPARISON OF RESERVE CAPACITY AND DELAY
FOR LEFT TURNS AT A T-INTERSECTION Flpwp 1
COMPARISON OF RESERVE CAPACITY AND DELAY
FOR RIGHT TURNS AT A T-INTERSECTION Flpu!• 1
150
149
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A MFTHODOLOGY FOR USING DELAY STUDY DATA
TO ESTIMATE THE EXISTING AND FUTURE LEVEL OF SERVICE
AT UNSIGNALIZED INTERSECTIONS
By Marni Heffron (A)a and Georgy Bezkorovainy (H)b
INTRODUCTION UNSIGNALIZED INTERSECTION DELAY
The level of service at unsignalized intersections is
often overstated by the 1985 111ghway Capacity
Manual (HCM) methodology. The HCM analysis for
unsignalized intersections may show a LOS E or LOS F
operation with lengthy delays and, presumably, long
queues. However, from field observation, the
intersection functions relatively well with short
queues and minor delays on the approaches controlled
by STOP signs and no delays to mainline traffic. Many
reviewing agencies require the use of the HCH
methodology to determine level of service. However,
HCH states that "because the methodologies [for
calculating unsignalized level of service] result in a
qualitative evaluation of delay, it is also
recommended, if possible, that some delay data be
collected. This will allow for a better
quantification and description of existing operating
conditions at the location under study." HCM does
not, however, include a methodology to relate delay
study results for an unsignalized intersection with a
level of service designation.
HCH defines the level of service of an unsignalized
Intersection using "reserve capacity", an
analytically -defined variable that is not easily
field -verified. The procedure is based on the German
method of capacity determination at rural
Intersections. This method has not been extensively
validated or calibrated for U.S. conditions, nor does
it estimate delay in quantitative terms.
li
This paper presents a methodology to use delay study
data to determine the existing level of service and to
estimate future operating conditions at unsignalized
intersections. In developing the methodology, delay
studies were performed at more than 50 unsignalized
T-intersections in eastern and central Massachusetts.
Minor approaches of these intersections were
controlled by stop signs, yield signs and uncontrolled
(implied yield). The results of these delay studies
will also be compared to the delay calculated using
the HCH unsignalized intersection analysis.
This paper relies on the existing HCH methodology as
the basis to estimate existing and future level of
service from delay data. Until changes are made in
the HCH procedure, the existing HCH methodology for
unsignalized intersections will continue to be
modified to yield results that better approximate
existing and future conditions.
a Transportation Engineer
Bruce Campbell 6 Associates, Boston HA
b Vice President
Bruce Campbell 6 Associates, Boston HA
Delay was adopted as a measure of effectiveness for
signalized intersections in the 1985 HCM for many
reasons; two reasons are that the concept of delay is
understood by the user community and delay can be
measured in the field.3 The application of delay
for unsignalized intersections should follow this same
reasoning. The.Xeserve capacity is related to
average vehicle delay using the following equation
from the ITE Handbook2:
d — 1 (1)
(a - b)
d — average delay
a — service rate
b — side -street arrival rate
Recognizing that capacity is the service rate and
volume is the arrival rate at an unsignalized
intersection, this formula shows that the average
vehicle delay is the reciprocal of reserve capacity.
The average seconds of delay per vehicle is calculated
using the following equation:
Average Delay (sec/veh) - 3600 (sec/hr) (Z)
Reserve Capacity (veh/hr)
Table 1 shows the level of service designations which
correspond to reserve capacity and average vehicle
delay. Because the average delay per vehicle
approaches infinity as the reserve capacity goes to
zero, LOS F will be defined by any delay over 60
seconds. The average delay values for unsignalized
intersections shown in Table 1 are very similar to the
delay values used to define the level of service of
signalized intersections. Table 1 is taken from Table
10-3 in the HCH.
Table 1
Level -of -Service Criteria
For Unsignalized Intersections
Average **
Level of
Reserve Capacity
Stopped Delay
Service
(Pass Cars Per Hour)
(sec/veh)
A
> 400
< 9.0
B
300 - 399
9.1 to 12.0
C
200 - 299
12.1 to 18.0
D
100 - 199
18.1 to 36.0
E
0 - 99
36.1 to 60.0
F
*
> 60.0
* Demand exceeds capacity; extreme delays will be
encountered
** Calculated from Equation (2)
—1—
DELAY
MEASURED DELAY VS CALCULATED
Delay studies at unsignalized intersections are
'
relatively easy to perform and can be performed in
with a turning movement count at low
conjunction
volume Intersections. The observer measures the time
between when a vehicle stops for a stop sign or
,.
conflicting traffic and pulls onto the major street.
12
The measurement includes the time waiting in queue.
12
The, stopped delay is measured for random vehicles
turning left or right from the minor street or turning
.e
left from the major street. The average delay during
the peak hour is calculated using a modified
'
signalized Intersection delay equation:
0
Total Delay (sec) (3)
Average Oeley (aec/veh) •
Number of observations
p .
For locations with a shared lane for left and right
turns on the minor street, the stopped delay for each
movement should be kept separate if future conditions
will be projected from the data since the level of
service of each movement is calculated separately and
then combined as a shared lane movement. Special
consideration, discussed later, should be given to
shared lane approaches where the right turn delay will
be increased by a high left turn volume. The existing
level of service for the shared lane is the weighted
average of the combined movements.
Bruce Campbell & Associates performed delay studies at
more than 50 unsignalized intersections in eastern and
central Massachusetts. For all study locations, a
traffic count was also performed, and the level of
service was calculated using the IICM methodology. To
date, only a few delay studies have been performed at
4-legged intersections, so only the data for
T-intersections are included in this paper. The
average delay per vehicle was calculated using
equation (3). Figures 1 through 3 compare the results
of the measured delay and the calculated delay. The
curves are from regression equations relating
conflicting flow,and average delay. At this point
there have been no attempts to correlate the delay
data to another variable such as speed, movement
demand or type of control.
For all three critical movements at an unsignalized
Lntersection--the left turn from the minor street,
right turn from the minor street and left turn from
the major street --the measured delay was found to be
shorter than the calculated delay. These data suggest
that drivers are selecting smaller gaps than those
,recommended in the 1965 HCM. Using the methodology
described below to back -calculate to the critical gap,
it was found that at over 80 percent of the locations,
the critical gap for both the minor left and right
turn movements was less than 6.0 seconds.
It was originally suspected that the smaller gap size
determined for the study locations would result in
higher accidents rates at these locations. However,
most of the intersections studied had accident rates
less than 0.5 Acc/Million Entering Vehicles, and none
had accident rates over 2.0 Acc/MEV. In
Massachusetts, intersections with an accident rate of
less than 2.0 are not considered high accident
locations.
FIGURE I
CON FLIC111JG FLOW vS. AVRERAGE DELAY
rr, uun„or—iu unTr i ciGiT1--
0 0.2 0.4 o.e o.n
Ithweandd
CON(LICIING FLOW
. FIGURE 2
CONFLICTING FLOW VS. AVERAGE DELAY
LEFT IURN FROM MNOR $IREEI
0 0.2 0.4 0.e 0.e 1
IThausonds)
CONKICING rLOW
FIGURE 3
CONFLICTING FLOW VS. AVERAGE DELAY
RIGI 11 IL1RN IROM MNOR SI REEF
0.2 0.• ".e
1 Thoueonda)
CONI UCING FLOW
�f.IGLRAlED
I'A'y6 ED
Intersections with a shared lane on the minor approach
provided conflicting results for the left and right
turn movements. In many cases, the critical gap
determined from the delay data for the right turn was
higher than the gap determined for the minor left
turn. This phenomenon is most likely due to the time
a right turner spends waiting in queue behind a left
turner. Because of the queue, the measured delays for
the two movements were not dramatically different.
Since the critical gap calculation relies on the
movement's conflicting flow, the right turn gap
calculates to a higher value than the left turn gap.
Generally, the minor left turn is the most critical
movement at an intersection, and the delay data for
the left turn is not significantly affected by a
shared lane. In retrospect, if delay data
measurements did not include stopped delays in a
queue, then the calculated gaps would be higher for
left turns than right turns in all instances.
llowever, not recording delays in a queue would give an
unfair representation of existing field conditions.
To further illustrate the shared lane phenomenon
affecting right -turning vehicles, the results in
Figures 1 and 2 show a large disparity between the
calculated delays vs. measured delays. However, in
the case of right -turning vehicles, the measured
delays were only 2-3 seconds less than the calculated
delays. The presence of left -turning vehicles in the
shared lane had, most likely, a significant impact on
the delay values recorded for right -turning vehicles.
Further research on shared -lane approaches is needed.
ESTIMATING FUTURE LEVEL OF SERVICE
The following procedure is suggested to estimate
future level of service from existing delay data. It
relies on the existing BCH methodology, and basically
back -calculates from delay to capacity to determine
the gap being accepted by drivers. Once the gap is
determined, the future capacity and level of service
can be estimated using the same gap.
The capacity for an unsignalized intersection movement
can be determined from delay by rearranging equation
(2) as follows:
Capacity (veh/hr) " 3600 (sec/hr) ♦ Side Street Demand (4)
Average Delay (set/veh)
the BCH equations relate critical gap to "potential
capacity." The potential capacity for the left turn
from the major street and right turn from the minor
street are the same as capacity, but the capacity of
the minor left turn needs to be converted to potential
capacity discounting the impedance factor of the major
left turn. The impedance factor is determined using
the following equation (the (the variable names
correspond to the variables in HCM):
r C
I — 1 - 0.00138 100 x V4 1.2052 (5)
p4
I — Impedance Factor
V4 — Left turn volume from major street
Cp4 — Capacity of left turn from major street
The potential capacity of the minor left turn is then
calculated using:
Cm7 (6)
Cp7 I
Cp7 — Potential capacity of the minor left turn
Cm7 — Actual capacity of the minor left turn
(determined from delay data)
Using Figure 10-3 in the 1985 BCH, the critical gap
can be estimated from the potential capacity and
conflicting flow. Alternatively, the equations in
Karsten G. Baass' article "The Potential Capacity of
Unsignalized Intersections" (ITE Journal, October
1987, pp. 43-46.) can be used to determine the gap.
The estimated critical gap may be lower than 4.0
seconds for low volume locations, but it is
recommended that 4.0 be the minimum gap used. HCH's
Figure 10-3 also `shows the minimum critical gap to be
4.0 seconds.
Once the critical gap is estimated from the delay
data, the future level of service at a location is
determined using the standard ITCH methodology. This
methodology is not recommended for intersections with
high accident experience, or where vehicles on the
side street are forcing a gap in the major street
traffic stream. The following is an example of this
methodology's application:
EXAMPLE:
A delay study and turning movement count were
performed at the T-intersection of Lincoln Avenue and
Bristow Street in Saugus, Massachusetts. The PH peak
hour turning movement volumes and vehicle delays are
summarized below:
Average
Peek Hour Conflicting Delay per Maximum Semple
Movement Volume Flow Vehicle Delay Size
Minor Left 107 1227 13.7 64 92
Minor Right 33 653 5.4 28 31
Major Left 36 653 3.8 14 15
According to the BCH methodology, the left turn from
Bristow Street to Lincoln Avenue operates at LOS F.
The delay study data, however, show that the left turn
operates at LOS C.
The capacity of each movement is calculated using
equation (4).
Movement Demand Capacity
Minor Left 107 vph 370 vph
Minor Right 33 760
Major Left 36 983
The potential capacity of the minor left turn 1s
calculated using the impedance factor from equation
(5). The impedance factor is determined from the
demand and capacity of the major left turn,
— 1 - 0.0038(100 x 36)1.2052 _ 0.98
983
and potential capacity, Cp7 — 370 — 378 vph
0.98
-3-
The conflicting flow of the minor left turn — 1227
vph. Using Figure 10-3 in the HCM, a critical gap of
approximately 4.5 seconds is located for a potential
capacity of 378 and a conflicting flow of 1227. These
steps are illustrated in the flow chart in Figure 4.
Under the future conditions, the conflicting flow is
estimated to increase to 1400 vph, and the minor left
turn demand will increase to 170 vph. The future
potential capacity located on Figure 10-3 is 300 vph
for a gap of 4.5 seconds and conflicting flow of 1400
vph.
The actual capacity accounts for the impedance factor
(for this example the impedance factor is assumed to
be 0.98).
Cm7 — 300 x 0.98 — 294 vph
The reserve capacity — 294 - 170 — 124 vph,
and the average delay is calculated using equation (2),
Delay — 3600 — 29.0 sec.
124
The level of service for the future conditions will be
LOS D.
CONCLUSION
The methodology presented in this paper provides one
way to quantify the operation of an unsignalized inter-
section when the HCM methodology does not correlate
with field observations. Future operating conditions
can also be defined on the basis of existing
conditions delay data. The delay methodology should
not be used for intersections with high accident
experience or where vehicles on the side street are
forcing a gap in the major street traffic stream.
Further research is needed for intersections with a
shared lane on the minor approach since the right turn
delay is affected by the left turn movement. Data
collected for the left turn movement on a shared lane
approach should not be significantly affected.
Delay is a measure of effectiveness that should be
applied to unsignalized intersections because it is
easily measured and also easily understood. Future
revisions of the HCM methodology should include
delay.
n
L.
REFERENCES
1. Transportation Research Board, National Research
Council. "Research Problem Statements: Highway
Capacity", Transporation Research Circular Number
319. Washington D.C., June 1987, page 27.
2. Institute of Transporation Engineers.
Transporation and Traffic Engineering Handbook,
Prentiss Hall Inc.; 1952, pp. 499-536.
3. Roess, Roger P. and McShane, William R. "Changing
Concepts of Level of Service in the 1985 Highway
Capacity Manual: Some Examples," ITE Journal, May
' 1987, pp. 27-31.
—4—
FIGURE 4
ESTIMATING FUTURE LOS FLOW CHART
Existing Future
Conditions Conditions
Measure Future LOS
Delays I I Table 1
Avg. De4y I I Avg. Delay
Per Vehicle Per Vehicle
Equation (3) Equation (2)"
Capacity (f) I I Reserve Cap.
Movement Subtract
Equation 4 Demand
Impedance Actual
Factor Capacity
Equation (5) I Equation (6)
Potential Potential
Capacity Capacity from
Equation (6) HCH Fig. 10-3
Critical Gap Assume Same
HCH Fig. Critical Gap
10-3 for Future
4. Baas$, Karsten G. "The Potential Capacity of
Unsignalized Intersections", ITE Journal, October,
1937, pp. 43-46.
5. Transportation Research Board, National Research
Council. Hi hwav Capacity Manual, Special Report
209. Washington D.C., 1985.
I
I
A P P E N D I X E
F,
91
li
7
I
i
I
I
t M M= s M m== M M IMI m m r r
4C-.103 warm[ 11, Peak Hour Volume
The peak hour volume warrant is also intended for application when
traffic conditions are such that for one hour of the day minor street traffic
suffers undue traffic delay in entering or crossing the major street.
The peak hour volume warrant is satisfied when the plotted point
representing the vehicles per hour on the major street (total of both
approaches) and the corresponding vehicle per hour of the higher volume
minor street approach (one direction only) for one hour (any four
consecutive 15-minute periods) of an average day falls above the curve in
Figure 4-5 for the existing combination of approach lanes.
When the 85th percentile speed of major street traffic exceeds 40 mph or
when the intersection iies within a built-up area of an isolated community
having a population less than 10.000. the peak hour volume requirements
is satisfied when the plotted point referred to above falls above the curve
in Figure 4-6 for the existing combination of approach lanes.
FIGURE 4-5. PEAK HOUR VOLUME WARRANT
a
( 600
2 OR MORE LANES & 2 OR MORE LANES
w Q 500
H a 400
In a.
OR MORE LANES & 1 LANE
a- 1 LANE & 1 LANE
0 uJ 300 I
z
= 200
J
>> 100
a
= 400 600 800 1000 1200 1400 1600 1800
MAJOR STREET — TOTAL OF BOTH APPROACHES — VPH
*NOTE: 150 VPH APPLIES AS THE LOWER THRESHOLD VOLUME FOR A MINOR STREET
APPROACH WITH TWO OR MORE LANES AND 100 VPH APPLIES AS THE LOWER
THRESHOLD VOLUME FOR A MINOR STREET APPROACHING WITH ONE LANE.
11WHt 4-U. YtAK HUUH VULUNIt WAHHAN I
(COMMUNITY LESS THAN 10,000 POPULATION OR ABOVE 40 MPH ON MAJOR STREET)
S �
a.
= 400
wQ
F ¢ 300
ma
n
o eQ 200
z
2?
0 100
2
L� .
x 3 700 800 900 1000 1100 1200 1300
MAJOR STREET — TOTAL OF BOTH APPROACHES — VPH
'NOTE: 100 VPH APPLIES AS THE LOWER THRESHOLD VOLUME FOR A MINOR STREET
APPROACH WITH TWO OR MORE LANES AND 75 VPH APPLIES AS THE LOWER
THRESHOLD VOLUME FOR A MINOR STREET APPROACHING WITH ONE LANE.
,,-2. OR MORE LANES Et 2 OR MORE LANES
•
• MORE
LANES
&
LANEIII III■■I
rI
I�
A P P E N D I X F
1
r
t
I
I
I
I
1985 HCM: UNSIGNALIZED INTERSECTIONS Page-1
IDENTIFYING INFORMATION
AVERAGE RUNNING SPEED, MAJOR STREET ..............
40
PEAK -HOUR FACTOR .................................
1
AREA POPULATION ..................................
100000
NAME OF THE EAST/WEST STREET .....................
Horsetooth Road
NAME OF THE NORTH/SOUTH STREET ...................
Mitchell Drive
NAME OF THE ANALYST ..............................
klk
DATE OF THE ANALYSIS (mm/dd/yy)..................
5/6/92
TIME PERIOD ANALYZED .............................
noon
OTHER INFORMATION: Short -Term Total Traffic
INTERSECTION TYPE AND CONTROL
---------------------------------------------------------------------
INTERSECTION TYPE: 4-LEG
MAJOR STREET DIRECTION: EAST/WEST
CONTROL TYPE NORTHBOUND: STOP SIGN
CONTROL TYPE SOUTHBOUND: STOP SIGN
TRAFFIC VOLUMES
EB WB NB SB
---- ---- ---- ----
LEFT 45 10 23 7 ,
THRU 639 680 2 2
RIGHT 23 9 10 36
NUMBER OF LANES AND LANE USAGE
---------------------------------------------------------------------
EB WB NB SB
------- ------- ------- -------
LANES 2 2 2 2
1 6bi- I14l.gF 1 T .j F. I T, F•
CAPACITY AND LEVEL -OF -SERVICE Page-3
---------------------------------------------------------------------
POTEN- ACTUAL
FLOW- TIAL MOVEMENT SHARED RESERVE
RATE CAPACITY CAPACITY CAPACITY CAPACITY
MOVEMENT v(Pcph) c (pcph) c (pcph) c (pcph) c = c - v LOS
p M SH R SH
--------------------------------
MINOR STREET
NB LEFT 25 77 68 > 70 68 > 42 43 >E E
THROUGH 2 106 98 > 98 > 96 > E
RIGHT 11 682 682 682 671 A
MINOR STREET
SB LEFT 8 79 71 > 76 71 > 66 64 >E E
THROUGH 2 105 97 > 97 > 95 > E
RIGHT 40 670 670 670 630 A
MAJOR STREET
EB LEFT 50 497 497 497 448 A
WB LEFT 11 515 515 515 504 A
I
IA
A
SITE LOCATION
c
4
N
Figure 1
1985 HCM: UNSIGNALIZED INTERSECTIONS Page-1
�xtkW#YxtiWW**�ttY*ttt*1tX*WX�*t*WYYttx****xW��ixtW#*Wx*iWYWt1tXWWt*W
IDENTIFYING INFORMATION
AVERAGE RUNNING SPEED, MAJOR STREET ..............
40
PEAK HOUR FACTOR .................................
1
AREA POPULATION ..................................
100000
NAME OF THE EAST/WEST STREET .....................
Horsetooth
NAME OF THE NORTH/SOUTH STREET ...................
Mitchell Drive
NAME OF THE ANALYST ..............................
klk
DATE OF THE ANALYSIS (mm/dd/yy)..................
5/6/92
TIME PERIOD ANALYZED .............................
PM Peak Hour
OTHER INFORMATION: Short -Term Total Traffic
INTERSECTION TYPE AND CONTROL
---------------------------------------------------------------------
INTERSECTION TYPE: 4-LEG
MAJOR STREET DIRECTION= EAST/WEST
CONTROL TYPE NORTHBOUND: STOP SIGN
CONTROL TYPE SOUTHBOUND= STOP SIGN
TRAFFIC VOLUMES
EB WE NB SE
---- ---- ---- ----
LEFT 31 18 34 6
THRU 771 1094 3 3
RIGHT 34 28 18 47
NUMBER OF LANES AND LANE USAGE
--------------------------------------------------------------
EB WE NB SB
----------------------------
LANES 2 2 2 2
LANE USAGE LT + R LT + R
CAPACITY AND LEVEL -OF -SERVICE Page-3
POTEN- ACTUAL
FLOW- TIAL MOVEMENT SHARED RESERVE
RATE CAPACITY CAPACITY CAPACITY CAPACITY
MOVEMENT v(Pcph) c (Pcph) c (Pcph) c (Pcph) c = c - v LOS
P M SH R SH
MINOR STREET
NS LEFT 37 60 49 > 50 49 > 10 12 >E E
THROUGH 3 75 67 > 67 > 64 > E
RIGHT 20 618 618 618 598 A
MINOR STREET
SB LEFT 7 60 51 > 56 51 > 46 45 >E E
THROUGH 3 75 67 > 67 > 64 > E
RIGHT 52 507 507 507 456 A
MAJOR STREET
EB LEFT 34 284 284 284 250 C
WE LEFT 20 423 423 423 403 A
m= m= r m= m = = m i= m= m m m
1985 HCM: UNSIGNALIZED INTERSECTIONS Page-1
s:*xxx:x**��x�xx�xzx:***:sz:x:x�x*six*sx�xxx*x*x��x::*zxxx:*x*x::*x�x
IDENTIFYING INFORMATION
AVERAGE RUNNING SPEED, MAJOR STREET ..............
40
PEAK HOUR FACTOR .................................
1
AREA POPULATION ..................................
100000
NAME OF THE EAST/WEST STREET .....................
Horsetooth Road
NAME OF THE NORTH/SOUTH STREET ...................
Mitchell Drive
NAME OF THE ANALYST ..............................
klk
DATE OF THE ANALYSIS (mm/dd/YY)..................
5/6/92
TIME PERIOD ANALYZED .............................
noon
OTHER INFORMATION: 2010 Total Traffic
INTERSECTION TYPE AND CONTROL
---------------------------------------------------------------------
INTERSECTION TYPE: 4-LEG
MAJOR STREET DIRECTION: EAST/WEST
CONTROL TYPE NORTHBOUND: STOP SIGN
CONTROL TYPE SOUTHBOUND: STOP SIGN
TRAFFIC VOLUMES
---------------------------------------------------------------------
EB WB NB SB
---- ---- ----
----
LEFT 75 75 75 10
THRU 975 1025 10 10
RIGHT - 75 10 50 50
NUMBER OF LANES AND LANE USAGE
---------------------------------------------------------------------
EB WB NB SB
--------------
--------------
LANES 2 2 2 2
LANE USAGE LT + R LT 4 R
CAPACITY AND LEVEL -OF -SERVICE Page-3
--------------
POTEN- ACTUAL
FLOW- TIAL MOVEMENT SHARED RESERVE
RATE CAPACITY CAPACITY CAPACITY CAPACITY
MOVEMENT v(pcph) c (pcph) c (pcph) c (pcph) c = c - v LOS
P M SH R SH
------------------------ ------------------------ ---
MINOR STREET
NB LEFT 83 60 33 > 34 33 > -59 -49 >F F
THROUGH 11 75 49 > 49 > 38 > E
RIGHT 55 533 533 533 478 A
MINOR STREET
SB LEFT 11 60 33 > 39 33 > 17 22 >E E
THROUGH 11 75 49 > 49 ) 38 > E
RIGHT 55 538 538 538 483 A
MAJOR STREET
EB LEFT 83 317 317 317 234 C
WS LEFT 83 311 311 311 229 C
0
1965 HCM: UNSIGNALIZED INTERSECTIONS
Page-1
Page-3
.***rxz:x*xzx::axxxx******xx:xxxar.*.**********
CAPACITY AND
--------------------
LEVEL -OF -SERVICE
_________________________________________________
IDENTIFYING INFORMATION
_______________________________________________
___________
POTEN-
ACTUAL
___________
FLOW-
TIAL
MOVEMENT
SHARED
RESERVE
AVERAGE RUNNING SPEED, MAJOR STREET ..............
40
RATE
CAPACITY
CAPACITY
CAPACITY
CAPACITY
MOVEMENT
v(pcph)
c (Pcph)
c (Pcph)
c (Pcph)
c = o - V
LOS
PEAK HOUR FACTOR .................................
1
_______
P
________
M
_________ ____________
SH
R SH
____________
---
AREA POPULATION ..................................
100000
MINOR STREET
NAME OF THE EAST/WEST STREET .....................
Horsetooth
NB LEFT
83
60
7 >
7 7
) -86 -76
>F F
NAME OF THE NORTH/SOUTH STREET ...................
Mitchell Drive
THROUGH
11
75
15 >
15
> 4
> E
RIGHT
83
473
473
473
390
B
NAME OF THE ANALYST ..............................
klk
MINOR STREET
DATE OF THE ANALYSIS (mm/dd/yy)..................
5/6/92
SB LEFT
11
60
9 >
13 9
> -26 -2
>F F
TIME PERIOD ANALYZED .............................
PM Peak Hour
THROUGH
28
75
15 >
15
> -13
> F
RIGHT
83
335
335
335
253
C
OTHER INFORMATION: 2010 Total Traffic
MAJOR STREET
INTERSECTION TYPE AND CONTROL
_____________________________________________________________________
EB LEFT
110
145
145
145
35
E
WB LEFT
110
247
247
247
137
D
INTERSECTION TYPE: 4-LEG
MAJOR STREET DIRECTION: EAST/WEST
CONTROL TYPE NORTHBOUND: STOP SIGN
CONTROL TYPE SOUTHBOUND: STOP SIGN
TRAFFIC VOLUMES
_____________________________________________________________________
,
EB WB NB SB
----
____ ____ ____
LEFT 100 100 75 10
THRU 1175 1675 10 25
RIGHT 50 50 75 75
NUMBER OF LANES AND LANE USAGE
_____________________________________________________________________
EB WB NB SB
_______ -------
_______ _______
LANES 2 2 2 2
LANE USAGE LT + R LT 4 R
Roads
The primary roads and streets near Little Caesars are shown
in Figure 1. Horsetooth Road borders the Little Caesars site to
the north. It is an east -west street designated as an arterial
on the Fort Collins Master Street Plan. It generally has an
urban cross section with two 12-foot travel lanes in each
direction. Near the site, a 21-foot center lane is provided for
left turns. The extra width of the left turn lane is required to
accommodate the double left turn configuration at the
College/Horsetooth intersection. The posted speed limit on
Horsetooth Road is 35 mph.
The site will be served by Mitchell Drive to the south of
Horsetooth Road. Mitchell Drive is planned to run north/south,
parallel to College Avenue between Horsetooth Road and Bockman
Drive. Mitchell Drive is planned to be a two-lane street and
will function as a recirculation street similar to Mason Street
west of College Avenue. The intersection of Mitchell Drive with
Horsetooth Road will align with the main access to The Square
retail center.
There are currently traffic signals at the College/Horsetooth
and Horsetooth/JFK intersections. These signals are
approximately 1000 feet apart. No signal is anticipated at the
Horsetooth/Mitchell intersection in the future. Sight distance
is not a problem along Horsetooth Road.
Existing Traffic
Peak hour traffic flow is shown in Figure 2. Since the
restaurant will not be open in the morning, but will be open for
lunch, both noon and afternoon peak hour traffic data were
obtained at the intersection of Horsetooth Road and The Square
access. All raw traffic data are presented Appendix A.
Existing Operation
Existing peak hour operations were analyzed using the
volumes shown in Figure 2. The resulting operation levels of
service are shown in Table 1. Calculation forms for these
analyses are provided in Appendix B. Appendix C describes level
of service for unsignalized intersections from the 1985 Highway
Capacity Manual. Left turns out of The Square access are
currently experiencing long delays. These types of delays are
common for left turns at unsignalized intersections. Recent
research indicates that the 1985 Highway Capacity Manual
technique for stop sign controlled intersections overstates the
level of service. The delay per approach vehicle is 15-25
seconds in the noon peak hour and 18-28 seconds in the afternoon
peak hour. Based on the research papers provided in Appendix D,
the level of service is more appropriately defined as Level of
Service C/D and D, respectively. This information is shown in
Table 1.
5
W
1 �
N
Uj
(1989 COUNT)
ro
ro
co
4 N d
r � � �— 114/152 c�
�-- 301/600
282/263
i
230/219 r 45/31
343/438 6331763 —�
' 2061222 N r' N
LU
LU
cn
O
W
J
O
V
II
I'1
RM
IN
(1992 COUNT) (1989 COUNT)
v
on �— 51 /47
9/28 I co �— 601/961
�— 673/1083 / ` 0/— 20/13
�— 103199
I SITE 627/824 —�
18/16 -M to
1 �-
1 Q
a
RECENT TRAFFIC COUNTS
Noon/PM Peak Hour
LL
7
Figure 2
Table 1
Recent Existing Peak Hour Operation
Intersection
Horsetooth Rd/The Square
EB L
SB L
SB R
Operation
NOON PM
A C
E (C/D) E (D)
A A
(-) Level of Service based on delay criteria
Table 2
Trip Generation
Noon
P.M.
Peak
Land Use
Trips
Trips
Trips
Trips
i
in
out
in
out
Restaurant
30
30
50
50
Office
5
5
5
5
TOTAL
35
35
55
55
7
III. `PROPOSED DEVELOPMENT
Little Caesars is proposing to construct a 2,300 square -foot
restaurant and related 1,800 square -foot office building. The
restaurant will serve both sit-down and pick-up customers. The
office building will be occupied by approximately four to five
Little Caesars employees. The office building will also be used
as a training facility for new employees. However, such training
courses are not expected to coincide with lunch or dinner peak
periods of operation. Figure 3 shows a schematic of the site
plan of Little Caesars. As indicated earlier, two levels of
analysis were performed: 1) a short range future (1993), and 2)
a long range future (2010).
The street system in the area was assumed to consist of the
streets as they currently exist for all levels of analysis. The
only improvement that was assumed is the extension of Mitchell
Drive to the south of Horsetooth Road to provide access to the
site.
Trip Generation
Trip generation is important in considering the impact of a
development such as this upon the existing and proposed steet
system. Due to the unique characteristics of both the restaurant
and office building, standard trip generation factors would be
inappropriate for these uses. According to Little Caesars
management, this restaurant is expected to serve between 20 and
30 customers during the noon hour, and 40 to 50 customers during
the PM peak hour. To be conservative, the maximum number of
customers was assumed for both hours. Since the office building
will be used by five employees, it was assumed that each employee
would enter and exit the site during the two peak hours. This
assumption also provides a conservatively high trip generation
factor. Table 2 shows the expected trip generation for the noon
and PM peak hour. A trip is defined as having either an origin
or destination at the site.
In order to determine a level of other traffic that would
likely use Horsetooth Road near Little Caesars, it was assumed
that background traffic would increase at one percent per year.
This is consistent with recent growth in traffic on Horsetooth
Road. In the long range (2010), it was assumed that background
traffic would increase as reflected in the North Front Range
Corridor Study.
Trip Distribution
Two directional distributions were determined for the Little
Caesars site. The trip distribution for the long range
projections assumes Mitchell Drive has been completed to the
south to Bockman Drive and provides recirculation access to
College Avenue. The trip distributions are shown in Figure 4.
8
I
7,
l
L7
1
1
1
' SITE PLAN
(Not to Scale)
�---► Proposed Access
1
Figure 3