1. Mesoscopic Modeling Approach for Performance Based Planning
October 24, 2014

2. Background
Project Scrutiny
Federal Funding

3. RTP Project Evaluation Aftermath
Compared “Future Build” with a “Future No-Build” to calculate and prioritize B/C for each project;
Could only evaluate roadway capacity projects – not traffic operations;
Some B/C ratios were negative;
Difficult to isolate project benefits (“spill over” from adjacent projects).

4. Key Regional Travel Demand Model Features
Citilabs Cube Voyager 6.1.1
Trip Based (migrating to ABM)
Gravity Model for Trip Distribution
Regionwide network assignment, by mode and trip-purpose
Network assignment is static and aggregated into multiple-hour time periods (AM, MD, PM, & NT)
Assignment output does not account for operational or non- recurring delay.

5. Were We Using the Right Tool the Right Way?

6. Revised Approach

7. Why Go Mesoscopic? Refine Road Geometry
Validate Volumes vs. Observed Counts
Optimize Signal Timing
Time and Cost Efficiency
Performance Based Rankings

8. Subarea Approach Instead of Regionwide
Project 1
Project 2
Project 6
Macroscopic Model
Mesoscopic Model
Subarea Network OD

9. Existing Regional Model Calibrated Existing Model
Deployed Methodology
Existing Regional Model
Subarea Extraction
Import into Visum
Match Geometry Counts
OD Calibration
Calibrated Existing Model
Performance Measures
Existing
No-Build
Build
Existing 2010
Total Link Volume
Nobuild 2040
No-Build Growth Factor
NoBuild 2040
OD Matrix
Build
Build Proportion Matrix
Future
Calibrated Existing Model
Calibrated No-Build Model
Performance Measures
Calibrated No-Build Model
Calibrated Build Model
Performance Measures

10. Calibrated Assignment
1565, 1515, 1771
1340, 1350, 1470
659, 553, 9
208, 194, 205
719, 692, 455
Minola Dr
506, 485, 430
Fairington Rd
1334, 1265, 1347
871, 947, 1268
222, 231, 77
1239, 1149, 711
324, 328, 542
W Fairington Pkwy
Thompson Mill Rd
183, 168, 635
1085, 1030, 884
341, 366, 886
Panola Rd
Legend::
Observed, Mesoscopic, Macroscopic
905, 1005, 997
823, 788, 704

11. Intersection Analysis
Analysis Summary AM PM
Intersection
Existing 2010 Delay
(sec/veh)
AM (PM)
No-Build 2040 Delay
Build
2040 Delay
Minola Dr – Fairington Rd
49(59)
97(92)
34(52)
W Fairington Pkwy
25(29)*
100(145)*
8 (6)*
Thompson Mill Rd
13 (16)
17 (21)
11 (19)
Intersection Analysis
Legend
LOS A
C (25+)
B (10+)
D (35+)
F (80+)
E (55+)
No-Build
Existing
Build

12. Automated Performance Reporting MacroAM
Demand
(veh)
VMT
(mi)
VHT
(hr)
Delay
Speed
(mph)
Delay Per Veh
(s)
Existing 2010
3,306
2,402
82.5
18.2
29.1
19.8
No-Build 2040
4,231
3,012
146.3
65.8
20.6
56.0
Build 2040
4,282
3,242
113.6
27.1
28.5
22.8 PM
Demand
(veh)
VMT
(mi)
VHT
(hr)
Delay
Speed
(mph)
Delay Per Veh
(s)
Existing 2010
3,837
2,761
91.3
16.7
30.3
15.7
No-Build 2040
4,911
3,255
201.5
113.8
16.2
83.4
Build 2040
5,150
3,715
132.4
32.8
28.1
22.9
Total Cost
($)
Annual Cost
Annual Benefits
B/C
Ratio
10,474,594
677,107
1,268,396
1.87
Original Result: -0.46

13. Step 1 – Define Subarea
Done for all assignment scenarios (AM & PM for: existing, build, no-build)
Exported from CUBE as .shp
Imported automatically into as .ver network file

14. Step 2 – Subarea Trip Generation (Ps and As)
Populated based on TDM output volumes
VISUM automatically defined the zones based on network “dangles”
Red zones are actual centroid connectors; green are “external”

15. Step 3 – Edit Geometry Turn lane capacity and prohibitions
Imported signal control templates for cycle lengths and phasing
Very time intensive for a larger subarea

16. Step 4 – Subarea Trip Distribution (O/D)

17. B/C Summary (Before and After)
Project
B/C ID
Name
Type
Before
After
DK-065C
Panola Rd: Segment 3
Widening
-0.46
1.87
DK-065E
Panola Rd Up
-0.06
1.79
WA-003
Monroe East Connector
New Alignment
-1.47
2.71
CW-AR-003
I-85 South
Interchange
-1.94
3.75
DO-252A
Chapel hill Rd
-0.77
21.84
FA-236A
East Fayetteville Bypass
-0.94
22.00

18. Conclusion and Next Steps
Project-level analysis is more appropriate
Efficient calibration
Incorporated operational delay
Subarea geography is key
Data intensive process
First generation was only pseudo-DTA
Next RTP Update:
Individual macro-assignment, regionwide performance;
Combined macro-assignment, individual performance.

19. For additional information…
Kofi Wakhisi, Esq., AICP
Section Supervisor – Project Implementation and Partner Services
Reza Taromi, PhD, PE
Travel Demand Modeler – ARCADIS