VISSIM: 4th UK USER Group Meeting (June 17th 2004)

MVA was commissioned by West Dunbartonshire Council in September 2003 to undertake the Clydebank Transport Study, a major study of the transport needs of Clydebank. One of the principal deliverables of the Clydebank Transport Study was the preparation of traffic models of the Clydebank area, and this was undertaken using VISSIM. In addition MVA have also been commissioned for a number of follow-on studies using the validated VISSIM models. This includes work for West Dunbartonshire Council as well as Clydebank Rebuilt, the regeneration organisation responsible for several high profile projects in Clydebank.

VISSIM has been used extensively for the various projects in Clydebank, including the following:

· development and successful calibration/validation of detailed area-wide model for three separate time periods, using dynamic traffic assignment;

· cordoning of the area model to produce a Saturday town centre model;

· scenario testing of development proposals using validated models; and

· review of infrastructure requirements for a significant landmark development, including full 3D representation.

For the Clydebank projects the functionality of the VISSIM software has been exploited as much as possible. This has included the use of the following functions within VISSIM:

· employment of ‘Dynamic Assignment’ for route choice;

· use of Vehicle Actuated Programming (VAP);

· utilisation of existing and new link types, to reflect varying network characteristics;

· inclusion of bus lines and bus stop dwell times;

· vehicle interaction with pedestrian movements at crossings;

· addition of 3D static objects, including use of V3DM to create new buildings etc;

· creation of movie files; and

· generation of evaluation files for model assessment.

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Structuring a VISUM Model to Estimate OD Trip Tables from Traffic Counts for Gateshead (SENSOR project)

By Dr. Anett Ehlert (TORG - Univ. of Newcastle), Sergio Grosso (TORG, PTV), Prof. Mike Bell (Imperial College London)

Abstract

The SENSOR FP5 EU project has seen a fruitful collaboration between the Transport Operations Research Group (TORG - School of Civil Engineering and Geosciences) of the University of Newcastle upon Tyne, Imperial College London and Gateshead Council. One of the objectives of this work was to estimate OD trip tables from traffic counts and other forms of traffic network measurements. In addition to this, an analysis of the positions of existing detectors with a view to possibly increase their numbers is being carried out. Apart from the software development required, this work presents a number of interesting challenges which can be of interest to the attendees of the VISSIM User Group Meeting because they relate to how a network can be built quickly and efficiently, how sources and destinations of traffic identified, and how link flow measurements from another source can be ‘attached’ to the network. Although the core engine for the estimation was the Path Flow Estimator (PFE, TORG – www.ncl.ac.uk/pfe ) the task was made possible by its 2-way conversion from/to the VISUM format which is the format of the starting GIS network.

Given the full interoperability between the PFE, VISUM and VISSIM (for example the OD matrices generated by the PFE are compatible with VISSIM/VISUM) and given that source networks are available from Navteq in VISUM format for all Europe (www.dds.ptv.de/html/international/geo.international.europa.datastreets.html ), it is evident the potential of this procedure when modelling traffic for large networks.

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Adding an Extra Dimension to VISSIM

By Paulo Humanes (Babtie)

Abstract:

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Trams, Trains, Traffic, Peds, Airports – 3D visualization

By Jeff Knight (Halcrow Group)

Abstract:

Increasingly there is a need to provide high quality visualisation to involve clients and members of the public within the assessment and planning of new infrastructure. Visualisation of the schemes is now a reality that has been realised as part of the modelling processes with the availability of high quality 3D graphical imaging generated within the design process, combined with detailed modelling of the interaction between vehicles and the movement of pedestrians, trams, LRT, trains, etc. Architectural practices often have massing data and detailed 3D model structures that can be incorporated within models to great effect. Recent applications have included the Thames Gateway Bridge in London, London City Airport, Waverley station redevelopment in Edinburgh. Internationally, a large masterplanning exercise is being undertaken in Dubai expanding the city from 2 million to 5 million, part of which included the modelling and visualisation for Dubai Municipality of the development of the Garhoud transport corridor. New road and junction assessments have also been modelled for Sharjah. In Scotland Almondvale shopping centre has been modelled with high quality graphics to simulate the interaction between parking demand and rapid new development.

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Analysis of Person Delay in Generic Hypothetical Networks using VISSIM

By Muhammad Ishaque (Imperial College London) and Paul Clifford (Babtie)

Abstract:

Transport for London (TfL) has commissioned a study of the application of micro-simulation modelling for pedestrians. As part of this study Imperial College London are assisting Babtie Group with the testing of micro-simulation capabilities for the evaluation of user delay for hypothetical networks, including VISSIM.

User delay is an important measure of transport network performance. Ideally, absolute total delay for all network users would be minimized. Additionally, the proportion of people by purpose using each mode of transport, and the value of time lost in delay associated with each mode needs to be evaluated. Although well-established analytical methods exist to measure delay these are limited to specific measures and modes and are subject to time and space restrictions. This approach is not always effective when assessing a real world network comprising different motorized and non-motorized modes and diverse traffic policies. The problem is further complicated by the complexity of non-motorized micro engineering and behavioural issues and the difficulty and cost of acquiring detailed data in real world networks.

Micro-simulation offers an opportunity to overcome some of these issues, by allowing the testing of various hypotheses and ideas to an acceptable degree of accuracy. With increasing computing power, a number of trials can be carried out very quickly. The usefulness of this approach becomes more evident as the physical space covering the transport network increases. It then becomes possible to observe the affects of local interventions in the traffic management in wider zonal areas, not directly associated with the intervention. The research is using VISSIM to carry out a detailed study of a hypothetical network initially comprising fixed time signals, pelican and zebra crossings and including as transport modes; cars, bus services (with dedicated bus lanes), goods vehicles and pedestrians. The main initial objective of the exercise is to optimize network delay by modifying different pedestrian prioritization policies. As the project progresses further elements will be investigated, including the integration with multi-criteria assessment techniques. The main research project is aiming to report to TfL in September 2004.

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Modelling Integrated Transport Systems including Pedestrians and Adaptive Signal Control in VISSIM

By Mohsin Munshi (Mott MacDonald) and Sonal Ahuja (Mott MacDonald)

Abstract:

Modern transport systems aim to provide integrated solutions to the problems of congestion. Most of these systems include not only private transport, but also some proportion of public transport including bus, light rail and trains. The main objective of an integrated transport system is to streamline journeys and make travel faster, safer and more reliable. Integrated transport solutions are tailor made for individual users and indeed, it is the individual user at an atomic level that is at the core of such solutions. All transport users are pedestrians for some part of their journey. Public transport users who may have to interchange between two transport systems become pedestrians whilst using the interchange facilities. When pedestrian issues for example safety, delays and system connectivity are unaddressed, then the integrated system suffers as a whole.

Most modelling exercises and packages ignore the individual pedestrian or pedestrian journeys altogether. However, if the need arises to carry out economic appraisal of an integrated transport system we must take into account not only private and public transport users, but also individual pedestrians. Integrated transport systems complicate the objective of signal controls where there are trade offs involved between pedestrian safety, bus and light rail priority and reduction of delays to other road (car) traffic. A true integrated solution is one that looks at the needs and problems of all different users individually and tries to find a common path to address the individual issues.

This paper presents a methodology to model pedestrians and adaptive signal control that aim to provide an integrated transport solution using VISSIM microsimulation program. The West Croydon Interchange has been provided as a case study. The objective of the model was to investigate future planned developments on behalf of the London Borough of Croydon and advice on their effects. One of the aims of the project was to improve the current pedestrian environment around and between West Croydon’s train, bus stations and tram stops. Hence modelling the interaction of pedestrians with traffic signals, public transport systems and traffic was of paramount importance.

The developed model is multi-modal, featuring the movements of cars, goods vehicles, buses, trams and rail within the study area. It also comprises modelling of pedestrians on both a macroscopic and microscopic scale and accurately replicates the traffic signals in the region.

Dynamic assignment of pedestrian origin-destination movements was carried out in the exercise, attempting to replicate their route choices with reference to many of the factors which would influence this (based on past research), each given a weighting according to its relative level of importance. This differs from many other pedestrian models as they tend to concentrate on one aspect such as the avoidance of obstructions.

The model was validated to the observed vehicular and pedestrian movements. It was used to investigate better pedestrian connectivity between the rail station, LRT and bus stops. An adaptive signal control algorithm was developed to take into account pedestrian demand delays while providing LRT and BUS priority as well.

The study also highlights areas of further research to make the developed model more accurate and robust for modelling pedestrian route choice.

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Route 149 VISSIM Scoping Study

By Roger Pye (Transport for London) and Sara Rollason (Faber Maunsell)

Abstract:

The London Bus Initiative (LBI) is a partnership approach to improving bus services in the capital. LBI aimed to elevate travel by bus to such a standard that prejudice would be overturned. LBI examined how the whole bus route could be improved in a seamless way across borough boundaries, thereby delivering significant improvements for existing and potential bus routes.

As part of LBI One, three bus routes throughout London were designated as Quality Whole Route Plus (QWR+) routes. These routes were to benefit from a higher level of investment and the greatest degree of bus priority. These routes were:

• Route 115 (East Ham to Aldgate);

• Route 185 (Lewisham to Victoria); and

• Route 149 (Ponders End to London Bridge Station)

In 2000, FaberMaunsell were commissioned to produce the preliminary design schemes for Route 149. Since then FaberMaunsell have produced the detailed design drawings and undertaken the site supervision. In December 2003 Transport for London (TfL) requested that FaberMaunsell undertaken a scoping study of a section of Route 149 using VISSIM, a micro-simulation package. This report discuses the finding of the study.

The key objectives for this study were to examine the effects of various elements on bus journey times, the features investigated were:

• Illegal and legally parked vehicles;

• Increased general traffic flows; and

• Alterations to traffic signal timings.

The study compares the alteration in journey times for both buses and general traffic from the original road layout to the existing QWR+ layout and finally to the proposed Intense Bus Priority (IBP) scheme. IBP incorporates inset parking bays that can be used during the Off peak period.

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Sloane Square – Feasibility Study

By Joerg Tonndorf (Project Centre)

Abstract:

Sloane Square forms a major intersection in The Royal Borough of Kensington and Chelsea in London. In excess of 2500 vehicles travel through the square during the peak periods together with a large number of pedestrians and bus routes. The square embodies a large roundabout circling a pedestrian area. Traffic enters and leaves the square on six different legs. While one approach is signalised, pedestrian facilities (Pelican- and Zebra crossings) reduce the capacity of the remaining legs. Traffic is characterized by a lot of interacting movements, lane changes and temporary blocking situations. A very precise and sophisticated VISSIM model, regarding priority rules, link types and driving behaviour, needed to be built to replicate on – street conditions. Black cabs follow dynamic routing decisions to simulate taxi ranks.

Sloane Square is also a major international attraction, whilst also providing an important amenity to local residents and businesses. It is a major public transport interchange for both bus and the Underground. Hence, emphasis was put on modelling a complete 3D scenario, PT and pedestrian movements across the square.

The V3D Modeller was applied to create buildings, monuments and further elements portraying the original scenery.

In order to produce a realistic picture of pedestrians waiting at crossing facilities, pedestrians are interacting, unlike the default behaviour in VISSIM.

The design concept is intended to improve the environmental amenity of Sloane Square, whilst maintaining existing traffic levels and ruling out detrimental effects to busses. The design proposal includes the closure of two approaches and changing the existing roundabout junction into a single two stream staggered junction. Several proposed VISSIM models, supplied with optimized TRANSYT signal timings, provide queue length and bus journey time data to assess the various options.

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