Revisions in Aimsun Next for Collaborative Working
September 2025
Dimitris Triantafyllos
Senior Product Specialist
What is the Revisions feature?
The Revisions feature in Aimsun Next transport modelling software is designed to support teamwork by allowing multiple users to work on different parts of a transport network simultaneously.
Each user creates a separate revision of the base model, edits their assigned area, and later merges their changes back into the main network.
Main benefits of using the Revisions feature:
- Faster workflows: Teams of transport modellers can divide large networks into manageable zones, each assigned to a different modeller. Parallel editing speeds up workflows and reduces bottlenecks.
- Error Reduction: The Revision feature isolates changes to specific areas and uses buffer zones to minimise the risk of overlapping edits or accidental deletions.
- Auditability: The system tracks added, changed, and deleted objects per revision, making it easier to review and validate changes before merging.
How to use the Revisions feature: a step-by-step guide
1. Prepare the Aimsun Next Network file
To ensure effective collaboration using the Revisions feature in Aimsun Next, the network should be divided into distinct areas; one for each modeller (revision) in the team.
These areas must be clearly defined and separated by buffer zones. The buffer zone serves to prevent unintended modifications to objects outside a modeller’s designated area. For optimal protection, each buffer zone should include at least two nodes, creating a sufficient margin that minimizes potential conflicts between revisions.
Each modeller must work exclusively within their designated area and avoid deleting or modifying any objects outside their boundaries. Maintaining the area limits is essential to preserve the integrity of other team members’ work and prevent conflicts between revisions.
Example of an Aimsun Next Network split into two different areas; one for each modeller (Claudia/Carles):
2. Create Revisions
Each revision is given a unique ID range and name (e.g., “Carles” or “Claudia”) to prevent object conflicts.
To create a new Revision, select Project < New Revision…:
In the Create New Revision dialogue, locate the Base Document, give the revision a name and specify its location. The folder should be accessible to the whole team.
For each revision, assign a unique Name and a New Initial ID. This ID determines the starting point for all new objects created within that revision. Every new object will automatically receive an ID that begins with the specified number.
For example:
- In Revision 1 (named Carles), the first new object is assigned ID 1,000,000, the second 1,000,001, and so on.
- In Revision 2 (Claudia), new object IDs begin at 9,000,000.
This approach helps maintain clear separation between objects created in different revisions and simplifies tracking and conflict resolution. See the screenshots below:
3. Edit, Delete and Create Objects Locally
Users can edit, delete and create new objects such as geometry objects (sections, nodes, roundabouts…), reserved lanes or section objects (detectors, controllers, stops…).
When working with revisions, complexity increases due to the interdependencies between objects. Special care is required when modifying any object that is linked to others, as changes may impact the entire network and affect multiple Revision Regions.
Examples of Complex Revision Scenarios
- Control Plans: A control plan defines signal groups and timings for a set of junctions. Editing one junction may affect the entire plan and its associated regions.
- Transit Lines and Sub Paths: A transit line or sub path that spans multiple geographic areas may be edited in separate revisions. If sections or turns along the route are modified in one or both revisions, inconsistencies or conflicts may arise.
- Traffic Management Actions: Modelers working in separate revisions may add, modify, or remove traffic management strategies. If these actions are assigned to the same scenario, coordination is essential to avoid conflicts.
For guidance on handling these situations, refer to Managing Revisions.
4. Review Changes
First, it is recommended that while work is being undertaken in revisions, then the base model is kept unchanged until the revisions are consolidated.
The objects added, changed or deleted in a Revision can be reviewed from the Project Context menu Revision Info.
The Revision Info panel shows all modifications, helping users catch unintended edits outside their zone. This window will show you if you have accidentally edited or deleted an object outside your working area.
5. Consolidate, Detach or Reverse Safely
Once all revisions are complete, three options are available:
- Consolidate Revision: Transform a revision into a full network by joining the base and the revision information in the same file. This can be done through Project/Consolidate Revision. This also updates object IDs in the base revision.
- Detach Revision: This option would be used to set a revision free from the base model either to be worked on in future in isolation or to create an archive copy, for example at the end of an option test. It copies the base into the revised model and keeps the base and revision as two independent documents.
- Revert Selection to Base: This option would be used to revert the desired changes of a revision in case there are conflicts between revisions. An object that has been saved in a revision can be reverted to the same state as it is in the base and the revision changes discarded. Select the object, or multiple objects in the 2D view and select the Revert Selection to Base option in the Project menu. The revision will be saved and closed, then, on re-opening it, those objects will have been removed from the revision, will be read from the base Aimsun document and therefore will be unchanged in the revision. Since it is an experimental option, be sure that you keep a backup of the document before performing any action.
Check the Suggested Workflow to enhance teamwork and efficiently undertake a variety of tasks in less time.
Advanced Use Cases
- Scenario Management: Revisions are not just for teamwork, but also for testing different traffic scenarios independently.
- Scripted Consolidation: Internal teams have developed scripts to automate revision merging, reduce conflicts, and streamline daily updates.
- Cloud Collaboration: The new Geo Comment feature in Aimsun Next 26 builds on Revisions by enabling real-time threaded feedback and issue tracking within cloud-hosted models.
