Traffic simulation models used in Utrecht
1. Macroscopic models
The
Traffic Model for the Utrecht Region (Verkeersmodel Regio Utrecht, VRU) is a simultaneous macroscopic regional
model for three means of transport during a morning and an evening rush hour
and a whole 24-hour period.
On the
basis of the VRU model, the following sub-models were developed for the same
years:
§
a simultaneous (unimodal)
24 hour-model (VRU) for a working day in three transport alternatives (car,
public transport and bicycle) and five separate travel goals
§
a (unimodal)
model (VRU) for automobiles for the morning and evening rush hours: Rush-hour
Model for the Utrecht Region (Spitsmodel Regio Utrecht, SRU) and for a 24 hour period
§
a (unimodal) model for public
transport for a 24-hour period.
The
mentioned 24-hour model for automobiles is used for environment calculations.
The VRU-model is based on 1998 as the reference year and contains forecasts for
2015, the plan year.
The VRU-model is actualised at present to 2002, the new
reference year, and 2020 as the new plan year. The freight transport is also
developed separately in this model. For environment aims the model is also
built from three simultaneous models of different parts of the day consisting
of the morning peak, the rest of the day and the evening rush-hour.
Brief description:
The VRU
and SRU models have been built up from 2500 traffic areas and cover the whole
of the Netherlands. The city of Utrecht is part of the study area and contains 400 zones.
The model
includes three networks for automobiles, bicycles and public transport. Roads,
districts and residential areas have not been included.
The
origins and destinations of the zones have been established in matrices.
Five
motives for commuter traffic have been included in the models:
§
Home-shops
§
Home-school
§
Home-work
§
Business
§
Other.
The journeys are
calculated on the basis of generalized costs.
They are stored in various matrices and allotted to the networks. Allocations are possible in the form of 'all
or nothing’ or with 'capacity restraint'.
Description of the input and output data:
Input:
Geographical basis with area
division (zoning) per 4-digit postal code.
Per zone:
§
Inhabitants and jobs
§
Student places
§
Locations for living and
working.
Network for automobiles,
bicycles and public transport.
Control data: OVG
(study of mobility behaviour), counts, vehicle registration study, possession
of driving licence, housing occupancy, people entering
and leaving public transport.
Output:
Origin and destination matrices per motive and mode of
transport.
Networks
(automobile, bicycle and public transport) with model data and count control
points.
Connections between zones and networks.
Allocations of the journeys from the matrices to the
network (vehicles).
Intensity ratios (I/C).
Data of the filling of areas on the map.
Various analyses at matrix and network level.
Validation of the model:
The
matrices are calibrated to reality by rearranging (on a limited scale) the
matrix cells to local deviations. In a later stage, finer rearrangements are
made at a stretch of road level. For
large flows, the reliability of the models is ± 10-15%; for the smallest flows
± 10-20%.The testing material mainly consists of OVG (study of mobility
behaviour) data and counts.
Availability of the model and model results:
The total model dataset can be
supplied on a CD-ROM and can be processed with the TRIPS and Omnitrans software or another macroscopic model
toolbox. The data can be supplied in CSV
format and is file-oriented.
The VRU
and SRU models are being developed on a regional level. The model’s manager is the Utrecht Region
Board (BRU). Model use by non-regional
partners is viewed per case by the BRU as manager. The model dataset can be requested at the
Utrecht Region Board.
2.
Microscopic models
In traffic
studies (e.g. the development of infrastructure), dynamic micro simulations are
made using the VISSIM software-package or adviser-bound simulation models, such
as Aimsum, Integration and Paramics.
The VISSIM simulation package is considered to be the standard for all traffic
micro simulations.
It is
expected that in the near future a mesoscopic model
will be developed for the city region.
This will require collaboration with regional administrative partners.
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