The primary objective of the project is to increase understanding of the requirements for the effective implementation of a traffic information system using variable message signing (VMS).
Of particular interest are:
the validation of both off-line and on-line control strategy approaches designed to ensure that sign switching sensibly reflects current and expected traffic conditions;
quantification of driver response to VMS, particularly insofar as it reflects different network and message considerations; and
the implications of the interrelationship between driver response and the choice of effective VMS switching strategies for VMS system design and use.
Research has been carried out in order to increase understanding of the requirements for the effective implementation of a traffic information system using variable message signing (VMS).
Alternative approaches are examined with respect to the development of control strategies in the context of road networks in Scotland and Denmark.
A detailed feasibility study has been completed. This has resulted in a modified work programme, incorporating:
all assessments being conducted in parallel on the 2 networks, enabling a high likelihood of achieving transferable results;
more emphasis on the offline MCONTRM modelling approach to VMS strategy testing (this will assist in demonstrating the incremental value of a more sophisticated online control approach;
more thorough investigation of driver response both using the simulator and, more especially, in respect of evaluating real driver response.
The VALDIMIR driver response simulator is almost complete. This enables drivers to make journeys through a simulation of the real network using realistic representations of network features and of VMS information. The simulator is configured to indicate the nature of response to VMS in relation to information quality and type, available route options and driver characteristics.
Model representations of both networks for both control approaches are in hand.
Preparation of the implementation of the VMS systems is at an advanced stage in both networks.
The project comprises the following key technical areas:
(a) examination of alternative approaches to the development of control strategies in the context of road networks in Scotland and Denmark. This examination involves:
firstly, creating a simulation of traffic on the road network;
secondly, conducting off-line development and assessment of strategies; and
thirdly, conducting on-line trailling.
This process will be conducted in parallel for alternative approaches.
Three types of strategy will be assessed within the project:
simple rule based, not dependent on the development work conducted within the project. These provide a bench-mark against which more sophisticated strategies can be assessed;
strategies based on off-line modelling of problems scenarios; and
traffic responsive strategies based on automatic control theory.
(b) examination of driver response to VMS in the context of the two road networks.
Assessment of driver response to VMS is undertaken in two stages:
simulation, prior to their real introduction, of driver response to alternative message forms, message content or control strategies;
measurement of actual driver response
(c) evaluation of the impact of control approaches and of driver response in the context of field trials.
VMS message content;
form of message;
driver response to VMS
approaches for supporting VMS control strategy development;
the evaluation of benefits from VMS; and
requirements for VMS control system development.
The achievements expected in 1993 are:
completion and reporting of simulated driver response investigations;
substantial development of the software environment for the on-line control approach;
off-line control strategy testing, evaluation and selection for real implementation;
set-up of the evaluations of real VMS operation; and
network VMS systems completed or approaching completion.
The principal impact of the project is expected to be in drawing together the various issues which need to be considered for an effective VMS system design:
The integration of these issues has been substantially neglected to date and the project expects to be able to make recommendations for system configuration and design as a result of its investigations.
Contribution to standardisation
The project will contribute directly to guide-lines and standardisation in relation to VMS particularly in respect of:
Appropriate message content;
appropriate choice of control strategy; and
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