This document discusses traffic modeling methodology and documentation. It emphasizes the importance of data validity, defining the appropriate temporal and spatial boundaries of the problem, understanding the problem type, and effective documentation. Several techniques for documentation are presented, including lane-based schematic diagrams, congestion heat maps, system efficiency graphs, and queue progression graphs. These visualization techniques help convey the key issues without extensive text. Effective documentation tells a story and is transparent, while focusing on the right audience and level of analysis.

1. Imagine the result
Simulation Data Analytics
Traffic Modeling
Shubhendu Mohanty, PE
July 2015

2. Imagine the result
Methodology
Development
Data Collection
Data AnalysisDocumentation
Traffic Modeling Overview
What can still go WRONG?

3. Imagine the result
1. Data Validity Traffic
Counts
3. Problem
Type ? ?Right Focus
2. Problem
Size
Temporal
Boundary
Agenda
4. Documentation
Presetting
the Solution
Discuss:

4. Imagine the result
Traffic Volumes
Output
Simulation Model
1. Data Validity

5. Imagine the result
 Peak Hour
Volumes
 Daily Volumes
 No non-recurring
congestion
 No weather delays
 No equipment
malfunctioning
 Right corridor and hours
are captured
We Ensure Quality By:
1. Data
Validity
When we collect THROUGHPUT instead of the DEMAND!

6. Imagine the result
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FlowRate(Veh/Hr)
Time of the Day
Measured Flow
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FlowRate(Veh/Hr)
Time of the Day
Measured Flow
Anticipated DemandCalculated Demand
Typical Peak
7:00 to 9:00 AM
Typical Peak
4:00 to 6:00 PM
Traffic Count Along I-285 EB
Demand Rate
=10500/HrThroughput
=8500/Hr
Demand
=8500/Hr
Throughput
=7500/Hr
Throughput Vs Demand
1. Data
Validity
2000 Veh/Hr
1000 Veh/Hr
Unusual Dip in the
Flow Rate
Early Peaking

7. Imagine the result
I-285 @ SR 400
Int. Project Area
I-285 and SR 400 Interchange
Demand
Estimating
Demand
1000 Veh/hr
(0 Veh/Hr)
2000 Veh/hr
400 Veh/Hr
1500 Veh/hr
(175 Veh/Hr)
Backed up Demand
AM (PM)
4.0 Miles
(1.0 Mile)
2.0 Miles
(No Queues)
3.0 Miles
(0.5 Miles)
No Queues
Queues
AM (PM)
1. Data
Validity
Back of the Queue
SR 400 SB , 7:00 AM

8. Imagine the result
2. Problem Size
 Temporal boundary limit is the length of traffic ANALYSIS
PERIOD.
 Necessary to capture the VARIABILITY of demand and
congestion.
Temporal Boundary Limits

9. Imagine the result
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Traffic Count @ SR 400 SB,
Georgia
2. Problem
Size
Flow(Veh/Hr.)
Time
Temporal Boundary Limits
Measured Flow
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Speed(mph)
Speed(mph)
Peak
Hour
Peak
Period

10. Imagine the result
AM Peak PM Peak
Shoulder Hr 1 83.50% 91.78%
Peak Hour
100%
(7:30 - 8:30)
100%
(3:15 - 4:15)
Shoulder Hr 2 90.50% 90.36%
Shoulder Hr 3 85.22% 82.76%
Shoulder Hr 4 74.23% 69.13%
Analysis Hours
Analysis Periods
2. Problem Size
Shoulder Hour Volumes
10 Hours of
data and
analysis
I-285 @ SR 400 Interchange Analysis, GDOT

11. Imagine the result
? ?
3. Problem Type
Data Validity
10 Hours of
Analysis
Output
What to focus on?

12. Imagine the result
? ?
3. Problem Type
Direction of Travel
No-Build
Bottleneck
Higher Density
LOS F
Low Density
LOS A-D
Denied Demand
Denied Demand
New
Bottleneck
BuildHigher Density
LOS F
?

13. Imagine the result
4. Documentation
Our WORK is only as good
as the STORY we Tell!
What can go wrong
with it?
1. Incomplete
2. Targeted to the
wrong audience
3. Too much text
4. Non transparent

14. Imagine the result
4. Documentation
i. Lane Based
Schematic Diagrams
ii. Congestion Heat
Map
iii. System Efficiency
Graph
iv. Queue Progression
Graph
Techniques to
convey
the right solution

15. Imagine the result
4. Documentation
Input
Volumes
(vph)1
Density
(vphpl)2
Travel
Time (sec)
Avg.
Speed
(mph)
Segment
Length
(ft.)
North Boundary to I-295 off ramp 6,550 19 64 65 6057
between I-295 ramps 3,670 13 70 68 6983
I-295 onramp to OSA off ramp 6,160 20 73 62 6663
between OSA ramps 5,210 18 22 67 2128
OSA on ramp to SR 9B off ramp 6,270 21 75 67 7377
SR9B off ramp to SR9B WB on
ramp4
4,070 13 49 63 4485
SR9B WB on ramp to SR9B EB
on ramp4
6,490 15 19 68 1917
SR 9B to rest stop 6,610 19 46 64 4328
between rest stop ramps 6,410 21 36 65 3395
rest stop to CR 210 off ramp 6,610 16 74 66 7191
between CR 210 ramps 5,040 16 33 67 3255
CR 210 on ramp to South boundary 6,220 20 63 67 6189
MOEs for year 2035 AM Peak Hour along Interstate 95
Southbound
Location
Build Original-Concept Alternative
Tabulation of Data
(Peak Hour Performance)
Rest Area
EntranceCR 201, Entrance CR 201 Exit Rest Area Exit
SB
Stick Diagrams (Peak Hour LOS)
LOS A to C LOS D LOS E LOS F
LEGEND
Conventional Methods
Covers Only: What and Where
Missing Info: Why, How and
When

16. Imagine the result
Link#
Density
Speed
Distance
LOS A to C LOS D LOS E LOS F
LEGEND : LOS Based on Freeway Density Veh/mi/ln
 Unhide information
 Geometry is self explanatory
 Easy to understand the issues
4. Documentation
i. Lane Based Schematic Diagrams
Volume
 Requires fewer texts to explain
concepts
 Customizable
Merits
Rest Area
EntranceCR 201, Entrance CR 201 Exit Rest Area Exit

17. Imagine the result
4. Documentation
Location (Highway Corridor)
Time(PeakPeriod)
Representation of congestion
across spatial & temporal
boundaries
ii. Congestion Heat Maps

18. Imagine the result
9:45 - 10:00 20 15 14 13 15 17 18 16 17
9:30 - 9:45 19 13 12 15 14 17 16 18 20
9:15 - 9:30 14 16 19 18 21 20 25 24 19
9:00 - 9:15 20 22 24 23 28 27 29 30 26
8:45 - 9:00 22 26 26 26 32 35 30 32 27
8:30 - 8:45 26 25 27 30 41 40 39 31 24
8:15 - 8:30 27 27 32 39 54 55 45 34 24
8:00 - 8:15 27 30 35 47 53 60 51 37 25
7:45 - 8:00 25 34 38 48 59 57 46 34 27
7:30 - 7:45 24 23 24 41 49 47 40 33 23
7:15 - 7:30 22 25 27 34 40 45 37 30 26
7:00 - 7:15 18 22 25 27 26 34 36 29 21
Space (Highway Corridor)
6:00 - 6:15 9 11 10 14 16 18 19 21 20
Freeway Density ( veh/mi/ln)
6:45 - 7:00 14 20 24 26 25 28 32 31 24
6:30 - 6:45 10 16 18 23 26 25 28 27 23
6:15 - 6:30 8 12 14 12 17 18 21 22 24
4
Time(AMPeakPeriod)
1
2
3
Congestion build-Up
and dissipation
Duration of congestion
=1.75 Hrs.
Origin of congestion
4. Documentation
ii. Congestion Heat Maps
a b c d e f
100% Congestion
Captured

19. Imagine the result
No-Build P.M. Peak
LOS based on freeway
density
Duration of peak more than
5.0 hours
Duration of peak
2.00 hours
50 % less
congestion under
build condition
I-285 @ SR 400 Interchange Analysis
Application of Congestion Heat Maps

20. Imagine the result
4. Documentation
iii. System Efficiency Graph
Peak Period (Time)
CumulativeVehiclesDenied
Entry

21. Imagine the result
0
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0 1 2 3 4 5
DENIEDVOLUME
PEAK PERIOD (HOURS)
DENIED ENTRY- 2019 PM PEAK PERIOD
No-Build Build
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0 1 2 3 4 5
DENIEDVOLUME
PEAK PERIOD (HOURS)
DENIED ENTRY- 2039 PM PEAK PERIOD
No-Build Build
6 7 85.5 7.0
Application of System Efficiency Graph
I-285 @ SR 400 Interchange Analysis
1.5 Hours of potential
reduction in congested
peak period
Reduction in delay under
build scenario
Point of queue dissipation
Point of queue dissipationPoint of queue dissipation

22. Imagine the result
4. Documentation
Queue Progression Graph
AM Peak Hour (By City of Sandy Springs)
Legend
2016 No-Build
2016 Build
Delayed
Vehicles

23. Imagine the result
How to Arrive at the Right
Solution?
1. Lane Based Schematic Diagram
Ditch the text, VISUALIZE data
Be mindful of the
FUNCTIONALITY
Take an OVERVIEW
approach
Be brief, but TRANSPARENT
Know your AUDIENCE
2. Congestion Heat Map
3. System Efficiency Graph
4. Queue Progression Graphs
Keys to Effective Documentation

24. Imagine the result
How to Arrive at the Right
Solution?
Validate the data
Be mindful of the temporal limits
Focus on the right analysis
Present a story, not just a report
Keys to a
Successful
Analysis

25. Imagine the result
Questions?
Shubhendu Mohanty, PE
Traffic Engineering Group Lead
Ph:770.384.6614
Shubhendu.Mohanty@arcadis-us.com