Legion for Aimsun - Integrated Pedestrian and Traffic Simulation

Legion for Aimsun is the first product to bring pedestrian and vehicle simulations together. It enables you to run Legion's validated pedestrian simulations within TSS's traffic simulation product, Aimsun 6.1.

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This means you can now run simulations in which pedestrians can negotiate crossings blocked by traffic; board and alight from public transport, taxis and private vehicles; as well as move along pavements and carry out activities like entering and exiting buildings, using ATMs and other varieties of street furniture.

Aimsun for Legion enables many types of studies that were not previously possible, such as determining the actual impact of high density pedestrian populations on traffic flow.

Before Aimsun for Legion, the results from measuring vehicle delay, travel speeds, and Level of Service (LOS) were often significantly skewed and unreliable.  It was also difficult to accurately assess the impact of traffic overspills on pedestrian crossings. In summary, it was a significant challenge to effectively measure any traffic system where pedestrians and vehicles shared the same space.


Implications for transportation

The need for safe and efficient public transportation keeps increasing. National and local government, transport bodies and other operators of public infrastructure are continually under pressure.

The problem is especially acute in the rail and metro sector, where unprecedented increases in passenger numbers compete with the physical limitations of available space. Growing populations and increasing urbanisation are the long term trends driving demand. The basic problem is easily described: how do you transport more people through fixed and limited transport infrastructure, within a reasonable time frame, at a reasonable cost?

Simply adding infrastructure is no longer good enough. More intelligent solutions are needed. Governments around the world are looking to develop transport infrastructure to address this problem, and the issue will be at the heart of city planning in the 21st century.

Effective transport is central to a city's economic competitiveness, and severe congestion is known to have an equally severe economic cost, estimated as high as between 1 and 3 percent of GDP in developed and developing countries.

Legion for Aimsun can help plan, simulate, test and analyse these new transport infrastructure designs.

Legion simulations

Legion is the only pedestrian simulation software that is calibrated with actual pedestrian measurements from around the world. It has been validated by independent agencies including London Underground, Madrid Metro and the London Fire Brigade.

Our pedestrian movement algorithms reflect actual preferred walking speeds, personal space requirements and the ability of individuals to make intelligent step-by-step decisions. Factors including evacuation times, levels of density, journey times, delays, route choices and many other metrics can be analysed.

Aimsun simulations

Developed and marketed by TSS (Transport Simulation Systems), Aimsun is a powerful, flexible traffic simulation programme. One of Aimsun's most distinctive features is the outstanding speed of its mesoscopic and microscopic simulators. Aimsun can simulate entire city centres much faster than real-time, while smaller models simulate over 20 times faster than real-time, producing otherwise unattainable analyses of traffic system effectiveness.

Aimsun enables its users to input data from almost every traffic forecasting software or shape file and simulation software, so that most available historical data, in any format, can be considered.

Aimsun models are subjected to rigorous independent testing and all Aimsun algorithms are completely open to public scrutiny, with every detail openly supplied in the User's Manual. With just under 2,000 users in 60 countries, Aimsun has become the software of choice in several cities, from New York to Brisbane.

Aimsun's sister application, Aimsun Online, is a real-time decision support tool for traffic management in large urban areas and regional networks. It integrates tightly with existing infrastructure and uses live traffic data feeds and high-speed simulations to forecast future traffic conditions, analyse alternative response strategies and propose optimal courses of action.

What does Legion for Aimsun make possible?

Police departments, emergency management agencies, city and state departments of transportation and city planners now have a reliable tool that enables them to examine the transportation network of an entire city centre, including all types of passenger vehicle, surface transit, bicycles, and pedestrians.

When paired with Aimsun Online, these agencies can simulate any condition or event to determine the outcome and develop proper responses, in real time if necessary.

Evaluating whole cities

Legion for Aimsun provides many exclusive features that enable you to model an entire city centre faster than real time. By including pedestrians in the models, a full working simulation of a city is now achievable. Such a simulation allows for detailed emergency evacuation studies and can provide the baseline for studying how land use or transport changes could affect traffic across an entire city. Detailed studies include:

  • Full city evacuation by vehicle and foot
  • Studying the effect of new highways, bridges and roadway changes on traffic and pedestrian patterns
  • Evaluating changes in traffic patterns caused by possible significant land use changes
  • Risk management for different evacuation scenarios across different areas of a city

Traffic engineering and planning studies

The simulation of vehicles and pedestrians together enables the accurate analysis of typical traffic and planning studies:

  • Accurate Vehicular LOS for right and left-turn vehicles where pedestrians are a factor
  • Crossing times and delays for pedestrians (including the effects of traffic spillover)
  • Realistic projection of the number and distribution of push-button calls at pedestrian crossings
  • Evaluation of pavement and sidewalk MPT plans both by LOS, journey time and other Legion metrics, including inconvenience and discomfort

Public transit assessments

Legion for Aimsun allows pedestrians within a simulation to board and alight from public transit vehicles. This makes detailed analysis of the following possible:

  • Near side vs far side bus boarding effects on traffic delay and signal progression
  • Proper sizing of street-car and light rail stations when shared with vehicular traffic
  • Effects of bus boarding on pavement flow and operations including BRT vehicles (both at bus stops and formalised queuing locations
  • Boarding and alighting effects of transit vehicles on different types of signal systems
  • Effects of taxi stands on pavement and kerbside travel lane usage (especially when that lane is a bus lane)

Stadia, major events and airports

In addition to public transit vehicles, pedestrians within Legion for Aimsun simulations can board and alight from private vehicles and taxis. This feature is particularly useful for studies concerning major events and places of interests such as stadiums, airports and train stations. Relevant applications include:

  • Lane requirements for airports that allow for both throughput requirement and kerbside studies
  • Kerbside usage at stadia and arenas
  • Major event operations, such as political conventions, parades and street fairs
  • Car parking studies

Environmental assessments

Simulating pedestrians and vehicles together means that is is now possible to:

  • Conduct LOS analyses at intersections,  ramps, pavements, crossings, intersection corners, roundabouts, metro entrances and stairwells in the same model
  • Provide emissions output for import into air quality models
  • Manage multiple data sets in the same model to evaluate the existing 'No Build' and 'Build' conditions in a single model


For more information, please contact info@legion.com