Multimodal Systems

PTV Vissim is the only microscopic simulation tool in the world that can be used to represent all modes of transport and simulate their interaction. In order to be able to accurately simulate route choice, lane choice, lane changing or vehicle following behaviour, various models are implemented in PTV Vissim that the user can tailor to the local conditions. This includes Wiedemann's car following model, a rule-based lane changing model and the Social Force Model for pedestrian dynamics. As a result, different multimodal scenarios can be modelled realistically and assessed with regard to the effect they have on traffic – whether for motorised traffic such as cars, lorries and buses, rail-based transport such as trams and trains, or non-motorised traffic such as pedestrians and cyclists.

Vehicles sharing space in PTV Vissim: Intersection with different modes of transport at Pont Kuss in Strasbourg, France.

Bicycle traffic: non-lane based behaviour

Copenhagen, Portland, Melbourne, Bogotá – more and more cities are endeavouring to promote cycling and to increase its share in the modal split. With PTV Vissim, this can be integrated into planning. This is made possible by the detailed consideration of mixed traffic. If motorists and cyclists have to share a road, they can drive side by side and overtake each other on the same lane. Regardless of the configuration of the lane marking, PTV Vissim can have vehicles with different widths interact with each other on a single lane and make their way through lateral movements wherever enough space for cutting in is available.

The simulation software models bicycle traffic with non-lane based behaviour. In PTV Vissim, cyclists always choose the lateral position that enables them to move as far as possible at their desired speed. Moving into gaps that favour forward movement and small distances to other nearby road users are taken into account and simulated.

Simulation of mixed traffic with PTV Vissim: Different kinds of vehicles (cars, scooters, bicycles) sharing and ignoring lanes.

Public transport

In order to represent public transport systems in detail, users can easily import their public transport models planned in PTV Visum into PTV Vissim or manually add them in the simulation software. Public transport lines, different public transport vehicle types, timetables, stops, stop types and dwell times can be specified and public transport priority signalisation can be modelled. The simulation then shows how well a planned timetable actually works, how many bus bays the bus station needs and whether the planned connecting times are feasible for the passengers. This makes PTV Vissim the ideal planning tool for multi-modal transfer stops. 

Pedestrians

In towns and cities, pedestrians, cyclists and motorised traffic sometimes meet in a relatively narrow space. Therefore the consideration of pedestrian flows and their interaction with nearby traffic events is a key component of traffic and urban planning. The add-on module PTV Viswalk allows pedestrian behaviour to be studied step-by-step. Here the software considers the free choice of direction that is typical for pedestrians and that is based on individual decisions and allows the user to freely configure the different pedestrian types. Inter-modal connection relations and complex vehicle-pedestrian interactions can be developed in PTV Vissim. Event and evacuation scenarios help planners and decision-makers to select the correct evacuation strategy for buildings, tunnels or stadia.

Simulating pedestrian movements in public transport stations.

Modelling freight traffic

In the case of freight traffic, weight is a factor because the driving behaviour of fully loaded vehicles is different from that of vehicles in an unloaded state. A wide range of freely definable settings in PTV Vissim means it is possible to specify the precise dimensions of any vehicle and to display loading states visually. The load weight can be modified by manual entry and finely adjusted by means of a COM script. As a result, driving processes can be authentically depicted in PTV Vissim and the acceleration force and braking processes can be visualised and analysed via the simulation.

Airports and shipping

The coordination of airport traffic is a logistical feat; correct timing is critical. At airports, simulation of apron traffic helps planners to analyse the logistical flow of ground traffic. The loading and unloading of auxiliary vehicles (catering, luggage, tanker) on the very limited space can be represented in detail and the level of service at the stops for the passenger shuttles can be assessed. In order to make the results even more accessible for decision-makers and the public, users can also visualise aircraft in their Vissim simulation – whether parked, taxiing to and from the runway or even in the air.

Similarly, the simulation can be used to represent logistical flow in shipping traffic and to visualise the processes of loading goods in a 3D view. This application is suitable, for example, for container ports where freight is transferred from ship to land or to motorised traffic.