Simulation Modelling and a Decision Support Tool for Managing Urban Congestion: The West Midlands UTMC Project
M Marin, S Ahuja, Capita Symonds, UK; A Giszczak, Transport Research Laboratory, UK
A state of art regional urban traffic control, monitoring and evaluation tool for the West Midlands UTC scheme is described to monitor and study the impacts of traffic control by integration of microscopic modelling with the real UTC and ATM control.
As the surface transportation system becomes more complex and broader in its coverage area, it is very challenging to accurately analyse and evaluate the performance of the urban system itself before implementing new control strategies and/or physical changes, one of the best alternative options is the use of simulation models. Fortunately, current computational technology has advanced such an extent that one can simulate a sizeable network of surface transportation system within a reasonable amount of time. Not surprisingly, microscopic traffic simulation models become one of the most popular tools for traffic engineers to conduct transportation system analyses and evaluations. The microscopic traffic simulation models have been used for various occasions such as evaluating geometry changes, traffic signal timing plan updates, or the benefits estimation of new Intelligent Transportation Systems (ITS) strategies.
The aim of the project is to develop a state of art strategic urban traffic control, monitoring and evaluation centre for the seven local authorities in West Midlands, Birmingham region of the UK. The outcome of the project is to provide a Tool which would be used in conjunction with the West Midlands Urban Traffic Control (UTC) Major Transport Scheme.
The central theme of the project is to look at urban congestion problems for the whole region not divide UTC control on the political boundaries of the districts. For understanding the network we are developing complex interlinked microscopic simulation models for over 1000 kilometres of road covering more than 1250 traffic signal sites in the West Midlands region of the UK (the second largest urban area in the UK after London) covering Birmingham, Solihull, Coventry, Dudley, Sandwell, Walsall and Wolverhampton.
The models along with a set of easy to use tools aim to understand traffic and environmental data from the region. It is first time the simulation models are linked to real time traffic control using SCOOT, MOVA and VA traffic control strategies that are central to the implementation of the UTC systems. The models accept data feeds from loop data and other sources update and inform traffic managers automatically.
The models are also linked to the highway network and include algorithms for Active Traffic Management (ATM) such as ramp metering and hard shoulder running which have a significant impact on congestion in the West Midlands
To this end the Tool will be used by non technical planners to assess the effects and impact of incidents on the road network and to provide workable mitigating options based on user defined criteria. The models support the Decision Support Tool (DST) which informs the UTC operator on both short and long term strategies to reduce congestion and environmental impacts of traffic signal operations. The core functionality of the DST is to test incidents ranging from vehicle breakdowns or accidents on particular sensitive sections of the road network to planned road maintenance, special events etc. The outputs from the Tool will inform what measures could be placed to in order to address a variety of criteria such as vehicle delay, vehicular queues, effects on emissions, pedestrian priorities, diversions, traffic signal settings etc.
Our solution requires two levels of models as part of the Tool. Meso-models using VISUM software are being used to test the effects of reassignment and ?incidents?. The incidents are attributed to the models via a bespoke user-friendly front-end interface. The resulting assignment is being used in conjunction with various bespoke built assessment packages to feed the micro level models in VISSIM where through the interface parameters such as signal timings can be adjusted accordingly to address the impact.
This significant project has many firsts with innovation on many fronts including realistic evaluation and monitoring of impacts of the scheme being achieved by integration of microscopic modelling with the real UTC and ATM control. Through this paper we intend to share our experiences in large scale simulation modelling for UTC and ATM control.
Association for European Transport