Editor

The Editor application allows you to interactively modify existing simulation scenarios. While the Builder focuses on generating scenarios from OpenStreetMap, the Editor enables fine-grained adjustments to the road network, lane permissions, and various properties that influence both routing and traffic dynamics in SUMO.

Selecting a scenario

After opening the editor, start by selecting one of the scenarios from your workspace. Once selected, the map loads the corresponding network and displays all roads, intersections and lanes. From this point on, all interactions take place directly on the map: selecting roads, inspecting properties, and applying modifications. Switching scenarios is possible at any time, but unsaved changes in the current scenario will be lost.

Map settings

To help you understand the structure of the network, the editor offers several visualisation options. These settings are purely graphical aids; they do not alter the underlying scenario.

Lane directions

When enabled, each lane is displayed with an arrow indicating its direction of travel. This is particularly useful on complex junctions or multilane roads where the driving direction is not obvious from geometry alone.

Turn arrows

Turn arrows show the allowed maneuvers at intersections: straight, left, right or combinations thereof. They are drawn directly onto the road surface, giving a clear impression of how vehicles are expected to move through junctions.

Lane connections

This option visualises SUMO’s internal lane-to-lane connections. These links determine precisely how vehicles switch from one lane to another when crossing an intersection. Understanding these connections is important when changing lane permissions or adjusting lane structures.

Selecting objects

Most editing actions begin with selecting a lane or a junction on the map. Click on an object to open its details in the sidebar on the right. The sidebar provides a structured overview of all relevant properties of the chosen element.

After selecting an element, the sidebar may display:

• the ID
• the current speed limit
• the set of allowed vehicle classes (permissions)
• traffic light properties

Editing lane properties

The editor currently supports several types of lane modifications. Each change is made directly on the selected lane and remains local until you explicitly save the scenario.

Changing speed limits

To introduce a new speed limit simply enter the desired value in the Speed limit field. The map will refresh after saving to reflect the new attribute. Speed limits are assigned per lane and may later influence routing and travel times during simulation.

Adjusting vehicle permissions

SUMO models access rights using vehicle classes (vClasses). These determine whether a vehicle type (car, bus, bicycle, taxi, truck, etc.) is allowed to use a given lane.

In the editor you can:

• restrict lanes to public transport only
• create bicycle-only or pedestrian-only lanes
• forbid heavy trucks on selected roads
• allow taxis but exclude regular car traffic
• or choose any custom combination of classes

A dedicated dialog presents all available vClasses as selectable cards. You can freely toggle which classes remain permitted. The resulting configuration is applied to the selected edge or lane and immediately reflected in the sidebar.

Working with multiple edits

You are not required to save after each modification. Instead, you may accumulate multiple edits in a single editing session. The editor keeps track of all unsaved changes.

Reverting changes

If you want to undo everything you have modified since the last save, use the Revert function. This discards the temporary edits and restores the scenario exactly as it existed in the current version.

Saving changes

Click Save to apply all modifications permanently in the SESAM backend.

When saving, several steps happen automatically: The scenario network is updated with your changes. The traffic demand (background traffic and flows) is automatically repaired where necessary. For example, if a modification invalidates a route (e.g. by removing access for a certain vClass or changing lane assignments), the system recalculates the affected paths. A new version of the scenario is created. The editor reloads the updated scenario so you can continue editing immediately.

Simulations reference the scenario version they were created with and therefore remain consistent, even if later versions differ significantly. This allows you to run simulations on older states of the scenario and compare them with results obtained from more recent versions.