VIKING Workshop
PTV
EXPO 2000 traffic
management with
VISUM-Online
Planung Transport
Verkehr AG
8 May 2001
Stumpfstr. 1
Dr. Klaus Nökel
D-76131 Karlsruhe
Tel. +49 721 96 51-0
Fax +49 721 96 51- 699
Internet: www.ptv.de
PTV AG
What is Visum-Online ?

basic traffic estimation / forecasting algorithms for traffic management
centres

extension of proven VISUM platform

jointly developed by PTV and Siemens

fully integrated with PTV Vision and Siemens Concert

Installations
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
Hannover (move GmbH)

München (part of federally funded research project MoTIV)

Antwerp, Belgium (under development)

Berlin, Germany (under development)

Shenzhen, China (in preparation)
PTV AG
Why VISUM-online?

Numerous ITS facilities are deployed to improve traffic conditions,
e.g. in Hannover:

32 VMS for dynamic route guidance on motor way

80 km of motorway with VMS speed control

twice daily tidal flow one-way traffic on major highway

3 parking guidance systems (City, EXPO, P&R)

direct access to signal control programs

Links to

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
Roadworks Information System

Command & Control System of police and fire brigade

Operations control system for public transport
Call Centre for mobility services
PTV AG
Why VISUM-online?

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Support decisions about traffic management measures through

display of current level of service (LOS)

preview of LOS for 30 - 60 minutes

forecast of effects on LOS of proposed traffic management
measures
PTV AG
Architecture of Visum-Online
Transportation Modelling (VISUM-online)
C: Prognose
Output
• Verkehrslage
• Verkehrslage in
15,30,45,60 min
• Prognose
nächster Tag
ODBC
graphical UI
• Datenvervollständigung
• Kurzfrist Prog.
• Tagesprognose
ODBC
graphical UI
Fij-Matrizen:
• Normalverkehr
• Veranstaltungsverkehr
Model
ODBC
A: Navigation
B: Planung
Input
Demand
ODBC
Input
Networks
relational database (Oracle)
Subsystem
Interface
Subsystem
Interface
Subsystem
Interface
Subsystem
Interface
Network
Traffic
Control
Traffic
Counts
Incidents
Dynamische Daten
• Baustellen
• Richtungswechsel
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LSA
Parkleitsystem
Park+Ride Info
Schleifen
Video
Infrarot.
External Data (Subsystems)
RDS-TMC
Polizei ELR
PTV AG
AG
Hannover: Available Data Sources

Traffic volume at selected detector loops
(motorway, signal controlled junctions)
Volume

Speed at delected detector loops (motorway)
Volume

State of variable message signs and route guidance

Messages from RDS/TMC radio warning system

Current roadworks and incidents

Car park status (percentage filled)

Major cultural events (with impact on demand)

During EXPO 2000: advance ticketing information

Weather
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Impedance
Impedance
Demand
Demand
PTV AG
Hannover: Output

Sensor fusion: GIS system allows simultaneous viewing of all
traffic-related information

Level of service (LOS): interpolation of most recent measurements
produces volume + speed on all network links

Short-term forecast: extrapolation of current LOS for next 30
minutes (traffic flow simulation)

What-if forecast: like short-term forecast, but with the assumed
effects of a proposed traffic management measure

Medium-term forecast: LOS for the next day based on historic trend
lines and current information about events, road closures etc.

Visualisation for traffic management operator and distribution of
traffic information via Internet, TV, Fax, email, print media
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PTV AG
Data Completion
VISUMonline
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PTV AG
Algorithm for Data Completion (1)


Input

OD matrix as initial solution

volume from isolated detectors
Algorithm


Principle


Path Flow Estimator (PFE) by Mike Bell, University of
Newcastle on Tyne, UK
Iterated equilibrium assignment with simultaneous adjustment
of impedances
Result
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
Estimated current OD matrix

Routes
PTV AG
Algorithm for Data Completion (2)


Input

Routes with volumes from PFE

measured volume and speed from detectors
Algorithm


Principle


Propagation algorithm by PTV
propagate q and v onto links in the neighborhood of detectors,
degree of confidence decreases with distance from detector
Result
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
volume and speed on all network links

reproduces inhomogenous distribution of vehicles along routes
PTV AG
Propagation algorithm: initial state
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PTV AG
Propagation algorithm : Result
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PTV AG
Algorithm for Short-Term Forecast


Input

Link volumes from propagation algorithm

OD matrices and routes from PFE

„Effects of measures“, e.g. roadworks, signal programs
Algorithm


Principle


mesoscopic traffic flow simulation (Dynemo)
movement of individual vehicles in accordance with
macroscopic indicators of traffic situation (density, avg. speed)
Result
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
30 - 60 minute forecast of volume and speed on network links

travel time forecasts on fixed routes
PTV AG
Short-term Forecast under scenario assumptions
Strategy A
Strategy B
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PTV AG
Algorithm for Day Forecast


Input

static network

„Effects of measures“, e.g. roadworks, signal programs

hourly OD matrices (base traffic + visitor traffic)
Algorithm


Principle


dynamic assignment
assignment in 15 min slices, taking into account unfinished
trips from previous slices, vehicles „jump“ in 15 minute steps
Result

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1 day forecast of volume and speed on network links
PTV AG
Day Forecast: Result
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PTV AG
Architecture of Hannover System
Multivision Display Wall
Editor
Traffic
Police
LAN
Management
Core
Database
Sensor Fusion
Analysis
Forecasts
LAN
Data Flow
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Traffic Volume, Weather, Incidents, Events
User Interfaces to
Subsystems
Variable
Message Signs
Parking
Guidance
Actuators
PTV AG
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PTV AG
Visum-Online
Display of detector readings
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PTV AG
Hierarchy of Networks
Networks differ in level of detail:
Forecast network:
~3800 links
~220 zones

Case 1:
Link represents future network,
therefore only present in planning
network

Case 2:
Link is part of subordinate network,
therefore only present in navigation
network

Case 3:
Main road, therefore present in all 3
layers, but with varying number of
intermediate nodes
Planning network:
~12000 links
~650 zones
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PTV AG
Traffic flow effects of incidents

Incidents and roadworks decrease the capacity of the infrastructure and
potentially lead to congestion.

This effect is uniformly modelled by decreasing qmax (capacity) and v0
(free flow speed)

Subsystems do not attach resulting qmax and v0 to roadworks and
incident messages, therefore traffic engineer in managament centre
appends this information

Generating complete alternate network versions for temporary effects is
too much overhead and complicates modelling simultaneous measures

Solution: Effects are stored as „infrastructure effect lists“ (German:
Netzwirkungslisten, NWL). Each NWL contains a list of tuples
(Network element, attribute, new value, validity period)
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PTV AG
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PTV AG
commit
set name and default validity period
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PTV AG
add to NWL root
select link
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PTV AG
commit
set effec
set validity period
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PTV AG
Hannover system: further functionality

demand editor (visitor traffic)

editor for scenario definition (incl. simulation)

difference view for comparing two simulation results

aggregation of detail data to historic trendlines

display of operating status, control of subsystem converters

user administration, user rights

...
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PTV AG
Hannover system: initial experience


Phased deployment

CeBIT 1999: basic visualisation of traffic counts

Autumn 1999: data completion and short-term forecast

CeBIT 2000: day forecast
Quality of results
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
Data completion and day forecast good, but detector coverage
still sparse in many areas

Short-term forecast currently only on motorways and freeways,
will be extended as more detectors come on-stream
12:00:00
02:00:00
02:00:00
01:00:00
00:00:00
23:00:00
22:00:00
21:00:00
20:00:00
19:00:00
02:00:00
01:00:00
00:00:00
02:00:00
01:00:00
00:00:00
8000
18:00:00
17:00:00
16:00:00
15:00:00
23:00:00
22:00:00
21:00:00
20:00:00
19:00:00
18:00:00
17:00:00
16:00:00
15:00:00
14:00:00
23:00:00
22:00:00
21:00:00
20:00:00
19:00:00
Mess
PFE
DYN15
DYN25
14:00:00
13:00:00
12:00:00
11:00:00
10:00:00
09:00:00
08:00:00
07:00:00
06:00:00
05:00:00
04:00:00
13:00:00
11:00:00
03:00:00
10:00:00
01:00:00
0
00:00:00
1000
09:00:00
2000
23:00:00
3000
18:00:00
17:00:00
16:00:00
15:00:00
14:00:00
13:00:00
12:00:00
11:00:00
10:00:00
09:00:00
08:00:00
07:00:00
8000
08:00:00
2000
07:00:00
06:00:00
05:00:00
04:00:00
03:00:00
02:00:00
01:00:00
00:00:00
23:00:00
22:00:00
06:00:00
6000
22:00:00
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05:00:00
04:00:00
03:00:00
02:00:00
01:00:00
00:00:00
23:00:00
22:00:00
PTV AG
upstream
of accident
accident
12000
10000
Mess
PFE
DYN15
DYN25
downstream
of accident
7000
4000
6000
5000
Mess
PFE
DYN15
DYN25
0
4000
PTV AG
Quality of Results

Measured and predicted (in absence of detector) traffic volumes are
almost identical (Flow_real vs. Vol_PFE)

Predicted speed has correct profile, but consistently too low (-> v0
needs to be recalibrated)
Volume [veh/h]
10000
Speed [km/h]
140
120
8000
100
6000
80
4000
60
40
2000
20
0
07:30
10.07.2000
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0
08:00
10.07.2000
08:30
10.07.2000
09:00
10.07.2000
09:30
10.07.2000
10:00
10.07.2000
10:30
10.07.2000
Flow_real
Vol_PFE
Vol_noPFE
Speed_real
Speed_PFE
Speed_noPFE
PTV AG
VISUM-online: a traffic manager‘s dream
for more information: klaus.noekel@ptv.de
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