A brief introduction to the new Simulation-Based dynamic Assignment (SBA) released in PTV Visum 16, as presented at the Virginia and Washington DC Joint SimCap Meeting, TRB 2017.

1. www.ptvgroup.com
Michael Oliver, PTV Group
January, 2017
PTV VISUM 16: SIMULATION-BASED DYNAMIC ASSIGNMENT

2. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 2
SIMULATION-BASED DYNAMIC ASSIGNMENT (SBA)
Distribute demand across
routes and time intervals
Network loading
Dynamic shortest paths per
OD and interval
Set of routes and costs per
OD pair and time interval
Demand per OD route and
time interval
Dynamic network state
Update set of routes
Loop until Dynamic
User Equilibrium

3. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 3
Network Loading:
 Mesoscopic simulation used for network loading
Mesoscopic Simulation:
 Uses the same science as in Mesoscopic simulation in
 Simplified Car Following Model
SIMULATION-BASED DYNAMIC ASSIGNMENT (SBA)
Travel at desired speed unless impeded
Temporal distance (in seconds) =
reaction time + time it takes to travel
the standstill distance

4. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 4
Mesoscopic Simulation II:
 Uses the same science as in Mesoscopic simulation in
 Simplified Car Following Model
 Lane Selection Model
 Junctions modelled with signal control and gap acceptance
 Realistic impact of signal offsets and coordination
SIMULATION-BASED DYNAMIC ASSIGNMENT (SBA)
Choice:
 Lane enables next turning movement
 Lane density

5. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 5
NETWORK MODELING FOR SBA
 Permitted transport systems for
links, turns, and connectors
 number of lanes, free-flow speed
 junction control
www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director

6. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 6
NETWORK MODELING FOR SBA
 Permitted transport systems for
links, turns, and connectors
 number of lanes, free-flow speed
 junction control
 junction geometry
www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director

7. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 7
NETWORK MODELING FOR SBA
 Permitted transport systems for
links, turns, and connectors
 number of lanes, free-flow speed
 junction control
 junction geometry
 TSys parameters
www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director

8. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 8
NETWORK MODELING FOR SBA
 Permitted transport systems for
links, turns, and connectors
 number of lanes, free-flow speed
 junction control
 junction geometry
 TSys parameters
 demand time series
7:006:00 8:00 9:00
Car
7:006:00 8:00 9:00
HGV
www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director

9. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 9
NETWORK MODELING FOR SBA
 Permitted transport systems for
links, turns, and connectors
 number of lanes, free-flow speed
 junction control
 junction geometry
 TSys parameters
 demand time series
 supply changes over time
7:30 – 8.00 a.m. 20 km/h
www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director

10. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 10
JUNCTION MODELLING FOR SIMULATION-BASED DYNAMIC ASSIGNMENT
Define for all nodes:
 Lane turns and major movements
 Signal timings and offsets
 Gaps, if non-standard
Visum will derive conflicts and check gaps for lower
ranked movements

11. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 11
SIMULATION-BASED DYNAMIC ASSIGNMENT – OUTPUT ANALYSIS
Time Interval: 06:00-06:10

12. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 12
SIMULATION-BASED DYNAMIC ASSIGNMENT – OUTPUT ANALYSIS
Time Interval: 06:20-06:30

13. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 13
SIMULATION-BASED DYNAMIC ASSIGNMENT – OUTPUT ANALYSIS
Time Interval: 06:30-06:40

14. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 14
SIMULATION-BASED DYNAMIC ASSIGNMENT – OUTPUT ANALYSIS
 Standard outputs
• e.g. volumes, travel time & speed per analysis time interval
 New for SBA
• Delay per analysis time interval
• Density
• Utilization
• Queue
• Simulation detail e.g. vehicles entered/exited
Time Interval: 06:40-06:50

15. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 15
SIMULATION-BASED DYNAMIC ASSIGNMENT – OUTPUT ANALYSIS
Showing all traffic that enters this link between 06:30 and 07:00
Time Interval: 06:20-06:30

16. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 16
SIMULATION-BASED DYNAMIC ASSIGNMENT – OUTPUT ANALYSIS
Showing all traffic that enters this link between 06:30 and 07:00
Time Interval: 06:30-06:40

17. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 17
SIMULATION-BASED DYNAMIC ASSIGNMENT – OUTPUT ANALYSIS
Showing all traffic that enters this link between 06:30 and 07:00
Time Interval: 06:40-06:50

18. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 18
SIMULATION-BASED DYNAMIC ASSIGNMENT – OUTPUT ANALYSIS
Showing all traffic that enters this link between 06:30 and 07:00
Time Interval: 07:00-07:10
 New: Dynamic flow bundle
• Extract volumes in the network that use a particular
object(s) in a particular time interval
• Extract flow bundle matrices (OD demand that uses an
object at a particular time) by arrival and departure time
window
 New: Dynamic skim matrices
• Average, or arrival/departure time related indicators

19. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 19
 Greater level of precision for demand
• Different hotspots at different times and in different places
• Suitable for larger networks  represent effect of long-distance patterns such as
long-distance commutes
 Greater level of precision for congestion
• Closer than ever to Vissim; the ideal stepping stone from Macro  Micro
• Lane-level interactions influence the result, e.g. queueing
• Signal offsets realistically represented
 Ideal use case for: heavily congested networks; transient congestion; time-
varying policies; incident/roadwork management; evacuation plans.
SIMULATION-BASED DYNAMIC ASSIGNMENT – SUMMARY

20. www.ptvgroup.com - Michael Oliver, PTV Visum Solution Director I page 20www.ptvgroup.com
Michael Oliver
PTV Visum Solution Director
Michael.oliver@ptvgroup.com
http://vision-traffic.ptvgroup.com