Upcoming release: Aimsun Next 8.4 public beta

February 8th, 2019

Coming out soon: the first public beta version of Aimsun Next 8.4 mobility modeling software.

There are some great new features to look forward to – we hope you enjoy testing them out!

Highlights – Summary

Highlights of Aimsun Next 8.4:

  • Enhanced modeling for Connected and Autonomous Vehicles (CAVs)

New CAV modeling enhancements include:

  1. The ability to adjust behavioural parameters by vehicle type and hence introduce a vehicle with different characteristics in its decision processes for lane changing and gap acceptance.
  2. An “External Agent Interface” that provides a simple method for connecting a driving simulator or CAV controller to an Aimsun Next simulation.
  3. A technical preview of the V2X communications software development kit (V2X SDK), designed to provide an extensible platform to include vehicle-to-vehicle and vehicle-to-infrastructure communications using standard CAV protocols or custom-developed, role-specific protocols.

The list of new features is not limited to CAV applications, and includes:

  • A new Destination Choice Experiment in the four-step process, which complements the existing Gravity Model
  • An importer for Sitraffic Office, the integrated status monitoring and centralized traffic control system from Siemens
  • An interface with Siemens PDM traffic signal controllers
  • HiDPI/ Retina Display optimization
  • Dark mode
  • Recording mesoscopic simulation

Further details on all of these new features below.

CAV modeling enhancements

New release: Aimsun Next 8.4 V2X SDK technical preview

You can now adjust all of the most significant behavioral parameters at vehicle type level, meaning that you can define vehicles that behave more or less conservatively in terms of lane-changing and gap-acceptance, not just car-following.

To take an example, you can now define an AV that:

  • strictly complies with the posted speed limit
  • maintains a longer headway from the preceding vehicle
  • overtakes only very slow vehicles
  • moves into a turning lane with more anticipation
  • doesn’t attempt aggressive lane changes
  • allows longer safety gaps at intersections

The External Agent Interface

If you want the AV to be driven by a different controller, you can plug an external vehicle control logic into the microscopic simulation using the External Agent Interface (licensed separately). The External Agent Interface sends via TCP/IP every simulation step, the position of the vehicles and the state of the traffic signals, and receives the updated position of the externally controlled vehicle. This extends the existing options of using API or microSDK.

Driving simulation

If you have developed the vehicle control logic in SCANeR, or you want to drive a vehicle in the microscopic simulation, we have completely redesigned the interface with this driving simulation software (requires a separate license).

New release: Aimsun Next 8.4

V2X SDK technical preview

For testing connected vehicle applications, we are releasing a technical preview of the V2X Software Development Kit (this requires a separate license).

With the V2XSDK you can create communication channels at the level of vehicle, road side unit and traffic management center; during the microscopic simulation, Aimsun Next takes care of generating and dispatching CAM messages to the appropriate recipients, taking into account transmission range, packet drop probability and latency. You only have to implement the actions taken by the vehicle, road side unit, or traffic management center based on the information they receive, for example, adapting the speed of the vehicle, controlling a traffic signal, or providing route guidance. This extends the existing option of using the API, giving a more detailed representation of the communication process.

Sitraffic Office Interface

Aimsun Next 8.4 has an interface to connect to the microscopic simulation emulators of the PDM traffic signal controllers developed by Siemens (this requires the Adaptive Controller Interface license).

Users of those controllers can export the geometry of the intersection along with the signal programs and the controller emulator from Sitraffic Office, and have a simulation running in Aimsun Next – all at the click of a button.

New release: Aimsun Next 8.4 Siemens Sitraffic Office

Sitraffic Office is a modular software suite from Siemens AG, which provides tools for traffic management based on a shared database of network assets and traffic data. Sitraffic Office provides workflow tools for integrated junction design, route planning, and network management and also integrates tools for dynamic signal actuation and co-ordinated signal control across junctions.

Destination Choice Experiment

The Distribution Scenario now includes a second type of experiment that implements a Destination Choice Model, which can be used in the Distribution Step of a Four-Step demand model instead of the existing Gravity Distribution Model.

HiDPI /Retina Display

The UI recognises when a HiDPI screen is in use (known as Retina Display on a Macintosh) and to present appropriately scaled icons and images

Dark Mode

A new Dark Mode to work with Dark Mode Windows themes.

New release: Aimsun Next 8.4 dark mode HiDPI

Recording Mesoscopic Simulations


The previous version of Aimsun Next already included the option to record and replay a mesoscopic simulation but only at a fixed interval of 5 seconds. This interval is now configurable in the replication editor.