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OCR for page 169
APPENDIX F
DESCRIPTION OF DATA SETS USED FOR MODEL EVALUATION
IN NCHRP PROJECT 3-48
The analytical models developed under NCHRP Project 348 are intended to predict signal timing and
estimate delay at a signalized intersection with traffic-actuated operation. To verify and evaluate
alternative models, several hypothetical data sets and one field data set were used In this study. For
hypothetical data sets, the predicted signal timing and delay were compared with results from TRAF-
NETSIM simulation. This appendix describes the intersection geometry, phase sequence, tragic
volumes and the actuated control parameters for all data sets used for the mode! evaluation. The
details and results of the evaluations are presented in separate sections ofthis report.
lIYPOTEIETICAL DATA SETS
To provide a general comparison oftraffic-actuated signal timing and delay prediction between HCM
Chapter 9 Appendix II method and proposed analytical model, several hypothetical data sets based
on four HCM Chanter 9 sample problems (SPI, SP3, SP4 and SP51 and seven hv~othetical examples
fit ~ TT~^ AT'-~ TV'- A TT'-r TT'-~ 1 It__ · ~ ·
<~1, Am, Am, Am, Am, ~o and am/' were used. Chinese data sets were selected from a group
of sample problem data sets prepared bv the Signalized Intersections Subcommittee ofthe Hi~hw.av
in- - ~ ~ r--r~-~~ I ~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~ ~~ ~ ~ ~ ~ J
Capacity Committee. Some of the traffic and operational data were modified to increase the range
of conditions included In this analysis.
NETSIM was used as the evaluation too! for both signal timing and delay models. The WHICH data
base manager program was used for the data input process. The ACT348 program, developed under
NCEIRP Project 348 to implement the proposed models and produce the signal timing and delay, can
be executed directly Dom WHICH. The equivalent Input file for NETSIM can also be created auto-
maticaDy Tom WHICH. For arty input file, NETSIM defaults were adopted when specific data were
not available.
Base Intersection Layouts
In order to intensively evaluate the proposed analytical models, possible practical intersection layouts
have been considered. There are a total often base intersection layouts (SPI, SP3, SP4, =l, ~2,
~3, HE4, =5, HE6 and HE7) used In this study which are presented as follows. In HCM sample
calculations, the geometry of HCM sample 5 (SP5) is similar to HCM sample ~ (SPl), so only the
intersection layout of S ~ is shown in Figure If-. This is a one-lane street for both north-southbound
approaches and a two-lane street for the east-westbound approaches. The intersection for HCM
sample 3 shown in Figure F-2 is a major CBD junction of two arterial streets. Both facilities have
~
four lanes, with exclusive lePr-turn lanes provided at the intersection on all four approaches. Figure
F-3 shows the geometry of HCM sample 4. This is a six-lane street versus a four-lane street. Each
approach has an exclusive ledc-turn lane. The hypothetical intersections of ~l, HE2, HE3, HE4,
YES, HE6 and ~7 are shown in Figures F-4 through F-IO, respectively.
Appendix F: Page 1
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~ -1t1~'
_ coo _
I, --.. ~ I
. . .
terra ~ ~
Figure F-~. Intersection layout for SP!
I, .. .
I, -,, 1
LE_I
, .
. . ~
-
1 '~
~ 1 -: 1 ~
1 1 ,..,,, 1 ~
.....
Figure F-3. Intersection layout for SP4
Figure F-5. Intersection layout for HE2
Appendix F: Page 2
Figure F-2. Intersection layout for SP3
ALLY
Figure F-4. Intersection layout for DIE!
-
GEOMh=Y r`~: ~o
~ia I
ma_ _GEOMh-~-xY
1 --- I91
411R 1 ~
Figure F-6. Intersection layout for EE3
OCR for page 171
K~C ~GEOMETRY
ia 11 ' 11
~'~
11 1
B'-....-i,.,l, Elm.
1 2T1]
l l -1 ~ 1
iC_ ~
ox -sent
1~
I_
craws
Figure F-7. Intersection layout for HE4
GEOlilh-1 BY
K._ ~ GEOMETRY
1~ ~!
I~L1
1=~t
it ~
1~ IL
Figure F-~. Intersection layout for HE5
Figure F-9. Intersection layout for HE6
Phase Sequence. Traffic Volume and Actuated Parameter Range
GEOUE=Y
Figure F-IO. Intersection layout for :HE7
Besides the intersection layout, phase sequence, traffic volume and actuated parameter range wall
influence the signal timing and vehicle delay. The hypothetical data sets cover eight different cases
of phase sequences. The following figures show the cases in the north-south direction:
Figure F-l I: Case I: phase sequence for simple permitted turns
Figure F-12: Case 2: phase sequence for leading green
Figure F-] 3: Case 3: phase sequence for lagging green
Figure F-14: Case 4: phase sequence for leading and lagging green
Figure F-15: Case 5: phase sequence for left turn (LT) phase with leading green
Figure F-16: Case 6: phase sequence for leading dual left turns
Figure F-17: Case 7: phase sequence for lagging dual leD turns
Figure F-~: Case S: phase sequence for leading and lagging with dual left turns.
Case 4 and Case ~ are interchangeable. For example, when northbound led turn volumes are heavy
and through traffic volumes are light, Case 4 may become Case S.
Appendix F: Page 3
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4''^ +',>1
x
4
x 1E~
7 8
Figure F-11. Simple permitted turns
~k'^~\,'~ !'~
1 .. ~
3 4
~ 1 ~
l
X
g
Figure F-13. Lagging green
>; Nt ~''^ ~- I,
l
. 1
Em
ft 14'`+',>1
3 4
:1 ~
7
~1 ~
8
Figure F-12. Leading green
Ny ~ 4''^ +\,' 4;
3
~ [I
7 8
Figure F-14. Leading and lagging green
~ >; 14''''','1
\ 11 ~
7 8
Figure F-15. LT phase with leading green
Appendix F: Page 4
\ ~ ~
7 8
Figure F-16. Leading dual left turns
OCR for page 173
k~^ +~1
EN 1 ~
7 8
Figure F-17. Lagging dual left turns
~ >t ~ >; I 4; ~
, 1
3 4
! ~
7 8
Figure F-18. Leading and Lagging with
dual left turns
Note that, for the shared lane scenarios, only permitted left turns were used. Compound left turn
protection was intensively evaluated at approaches with an exclusive left turn lane. The traffic
volumes and actuated parameter range used in the hypothetical data sets are shown as follows:
Traffic volumes per lane:
Minimum green time:
· -
maximum green time:
Detector length:
Allowable gap:
Ideal saturation flow rate:
50vph-350vph
50 vph - 800 vph
5 see- 15 see
10 see - 20 see
10 see- 30 see
30 see - 80 see
25 tic - 30 fit
2 see - 3.5 see
1800 vphgp! - 1900 vphgp}
(left turn)
(through plus right turn)
(left tum)
(through plus right turn)
(led turn)
(through plus right turn)
(placed at the stopline)
The summary of the characteristics of the sample data sets is shown in Table F-~. There are a total
of 27 data sets, some of which have subordinate data sets. The file name with an extension ".WC~'
indicates a WITCH input file. These two worksheets come Dom the output of the ACT3-48 pro
gram. For the data set with subordinate data sets, only the first subordinate data set is shown because
the others are similar to the first one. The phase sequences are determined by the control specifica-
tion in WHICH. They fall into the category of eight different phase sequences as mentioned before.
The specification and notation of the data set is addressed in the comment column in Table Fat. Data
sets from I-21 were used in this report for evaluating the proposed signal timing prediction model.
Data sets Tom ~ to 19 and 22 to 27 were used for comparing candidate delay models.
Appendix F: Page 5
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Table F-~. Summary of the characteristics of the sample data sets
No.of ~File Nme ~ Type of ~ Case ofPhase ~ Comments
Data Set ~(.wc l) | In. Layout ~Sequence |
1 | TEMP 1-8) | ~1 | Case ~| · dentical approach
Only through traffic
· Volume range Dom 100 vph
to 800 vph ~ Inc.=100 vph)
2 TEST(1-~) SP4 Case 6 · Exclusive LT lane
· NB and SB identical
. EB and Ah7B identical
· Volume range from 200 vph
to 1250 vph (Lnc.=150 vph)
for NB and SB
· Volume range Lom 400 vph
to 1 100 vph (Lnc.=100 vph)
~ for EB end WB
3 ~ ~] 1 ~HE1 ~Casel
4 | HEZ 1 ~HE2 ~Case 1 ~
5 | HEZ 2 ~HE2 ~Case 1 ~ · Only one lane for EB
_
6 ~ HE3 1 ~HE3 ~Case
7 ; HE4 1 ~HE4 ~Case 1- ~
HE4-2 HE4 Case 1 · Identical volume for each
l l l I approach
9 ~ HE; 1 ~HE5 ~Case
10 ~ SP} 1 ~SP1 ~Case 1 ~
Il ~ SP3 1 ~ SP3 T Case2 T
12 SP3-2 SP3 Case 3
13 ~ SP3 3 ~SP3 ~Case4 ~
14 SP3-4 SP3 Cases ~ & 5 · Case 1 for EB and WB
. Case 5 for NB and SB
5 1 SP3 5 ~SP3 ~Cases
~ 6 SP3-6 SP3 Case 7
Appendix F: Page 6
OCR for page 175
Table F-~. Summary of the characteristics of the sample data sets (continued)
1 7
SP4-1
SP4 Case 5 . Exclusive LT lane for each
~ approach
SP4 Cases 4 & 6 · Case 4 for NB and SB
· Case 6 for EB and WB
SP4 Case 4
HE6 Case 5
HE3 Cases 1 & 5 · Case 1 for EB and WB
· Case 5 for NB and SB
HE6 Case 6 · NB and SB identical
· EB and WB identical
· Volume range Dom 225 vph
to 825 vph ~ Inc.=75 vph)
for NB and SB
· Volumes are fixed as a
constant for EB and WB
SP3 Case 2 · Slight volume change for
EB and WB
. Fixed volumes for both NB
and SB
.
SP3 Case 6
HE7 Case 1 · NB and SB identical
· EB and WB identical
· Volume range from 90 vph
to 810 vph ~ Inc.=90 vph)
for NB and SB
. Volume range Tom 44 vph
to 396 vph ( Inc.=44 vph)
for NB and SB
HE6 Case 5 · Based on field data
SP4 Cases 4 & 5 . Exclusive LT lane
· Only one lane for NB and
SB in data set 6
· Case 4 for data sets 2, 4, 5
& 6 and case 5 for 1 & 3
18
19
20
SP4-2
SP4-3
MUSEUM(0 1-02)
21
22
23
24
25
26
27
H3IR
TESTN(l-9)
SP3-lEX(1-4)
SP3-lEX(5-6)
PERMIT(l-9)
MUSEUM(1-5)
HEAVY(1-6)
L I I
Appendix F: Page 7
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WELD DATA
To fi=her verify the analytical mode} for traffic-actuated signal timing prediction, a field study was
performed at the intersection of Museum Road and North-south Drive on the University of Florida
campus In Gainesville, Florida. In total, 32 hours of data were recorded over three weekdays. The
study periods included the morning peak the May peak and the afternoon peak. The site was a
four-legged intersection with one through lane and one exclusive 250-foot left turn bay on each
approach. The intersection layout is shown in Figure F-19.
At this intersection, standard dual-ring phasing was applied with protected plus permitted left turns.
The idea saturation flow rate was assumed to be 1900 vehicles/hour. Pedestrian recall was set in the
controller and the duration for WALK plus Flashing DON'T WALK was 22 seconds. The intergreen
time (yellow plus all red) was 5 seconds. The allowable gap setting was 3.5 seconds for through
movements and 2.5 seconds for left turns. Ah detectors were 25 feet in length placed at the stopline.
The minimum green time was set at 16.5 seconds for through phases and 10 seconds for leR turns.
The maximum Keen time was set at 45 seconds for through phases and 15 seconds for left turns on
Museum Road. The corresponding maximum Keen time settings for through and leD turn phases for
North-south Drive were 30 and 10 seconds, respectively.
IS Orion SB
t"'".2.
~2.-.
\:::
1 ~
Cob 1
1-
l~o
\1
.-.N
. . .
IS Drive NB
111 -^
Cl:
Figure F-19. Intersection configuration of Museum Road and North-south Drive
on the campus of the University of Florida
Appendix F: Page 8
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EXTRACTION OF SIGNAL TIMING AND DELAY ESTIMATES
FROM NETSIM SIMULATION
NET SIM was used as the simulation too} for the analytical mode! evaluation. NETS]M is able to
mode} eight-phase dual-ring controller explicitly, recognizing all of the phase-specific parameters.
NET SIM produces very detailed tables displaying several performance measures, including intermedi-
ate values. It does not, however, provide sufficient information on the operation of the controller
itself in the standard output tables. To obtain this information, it was necessary to develop a post-
processor to extract the operational data from the special file used to support the animated graphics
feature of NETSIM.
The actuated-controller data for each second of operation are recorded and stored in a text file that
is given a file name extension of ".F45" by NETSIM. A postprocessor was developed to read the
.F45 file and produce a summary of the operation. The postprocessor has been caned "NETCOP"
for "NET Sew Controller Operation Postprocessor?' [2~. It can produce phase-specific information
such as percent gapout, percent maxout, average cycle length, average phase time, adjusted cycle
length and adjusted phase time. A sample of NETCOP output is presented In Figure F-20.
NCHRP PROJECT 3-48: CAPACITY ANALYSIS OF TRAFFIC ACTUATED SIGNALS
ANALYSIS OF TRAF-NETSIM SIMULATION RESULTS FOR NODE 5
PHASE RING 1 RING 2
DATA 1(WBL) 2(EBT) 3(NBL) 4(S8T) 5(EBL) 6(WBT) 7(SBL) 8(NBT)
# Displayed66 4165662766
Pcnt Skipped0.00 37.881.520.0059.090.00
Pcnt Gapout100.00 92.68100.00100.00100.00100.00
Pcnt Maxout0.00 7.320.000.000.000.00
Pcnt Forced0.00 0.000.000.000.000.00
Average G/C0.47 0.150.380.470.080.45
G/C % Var16.70 84.7628.1716.79117.6422.04
Av Grn Secs25.53 7.8520.6425.474.3224.23
Secs % Var28.27 89.1326.3728.43123.0227.45
Adj Grn °25.47 7.8520.6425.414.3224.23
Adj Grn (D)25.47 7.8520.6425.414.3224.23
Occup on Grn0.29 0.050.190.270.020.21
Dwell Time Total Cycles Dwell
Adopted See
-- Cycle Length -
Sec Av Var Adj
Pcnt Variation
Green G/C
Controller 3565 66 4 54 21 53 48 54
Detector 3565 66 4 54 21 53 48 54
Figure F-20. Sample of NETCOP output
Appendix F: Page 9
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Note that two Ends of circle lengths are shown in the sample. The "average cycle length" is obtained
by dividing the total number of seconds processed by the total number of cycles. NETCOP trims
partial cycles at the beginning and end of the analysis to ensure that only whole cycles are
represented. The "adjusted cycle length" is computed by subtracting the number of seconds of dweD
time (i.e., the time during which no demand was registered) Dom the total number of seconds
simulated before dividing by the number of cycles. The "adjusted phase time" is computed according
to the adjusted cycle length. Since the adjusted phase time can represent the effective use of phase
time, it is adopted by this study for phase time comparison.
The last two lines In Figure F-20 show the awed time, average cycle length and adjusted cycle length.
The dweD time in the first line is called the controller awed time. This is the time during which no
demand was registered on any phase. The dwell time in the second line is caked the detector dweD
time. This is the time during which no demand was registered on any detector. In this study, the
controller dwell time was used and the phase times were computed accordingly.
Delay estimates can be obtained from the NETSIM output file. In this study, total delay was used
for the delay comparison. A program called NETSUM was developed to read the NETSIM output
file arid summarize the measure of electiveness (MOE). A sample of NET SUM output is shown in
Figure F-2 I.
SUMMARY OF TRAF-NETSIM MOE ~ S BY MOVEMENT
Simulati on Time was 3600 seconds
Measure
Northbound
1, 5)
Southbound
( 2, 5)
Westbound
( 4, 5)
r R L ~R L T R L r
Eastbound
( 3, 5)
R
Volune
Pent. Stops
Qume Delay
Stopped Delay 60.2
278.0 739.0
96.0 78.9
70.7 52.4
61.4 40.8
39.7
170.0 280.0
83.5 85.7
56.0 63.0
42.9
53.8
41.3 51.1
648.0
78.1
38.8
77.4 91.5
48.0 55.3
35.0 47.1
34. 1 46.0
202.0 888.0
87.2 87.7
59.9 65.0
47. 1 46.7
46.1 45.1
89.1
64.4
56.0
54.4
248.0
88.6 90.7
64.9 68.0
49.1
47.7
51.3
49.4
Figure F-21. Sample of NETSUM output
Appendix F: Page 10
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APPENDS F REFERENCES
Courage, K.G., Wizard of Helpful Intersection Control Hints (A Computer Software),
Research Version, Transportation Research Center, University of Florida, Gainesville, April
1995.
2.
Courage, K.G. and P-S Lin, NET SIM Controller Operation Postprocessor (A Computer
Software), Transportation Research Center, University of Florida, Gainesville, June 1995.
ACKNOWLEDGiVIENT
All of the intersection layout graphics were produced by the Signalized and unsignalized Intersection
Design and Research Aid (SIDRA), developed by ARRB Transport Resources, Ltd.
AppendlixF: Page 1
1
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Representative terms from entire chapter:
cycle length
