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.

Closing and reopening lanes

In addition to fine-grained vClass permissions, the editor can close an individual lane completely. A closed lane is treated as unavailable for all vehicle classes and is therefore excluded from routing. This is useful to simulate construction sites, accidents, temporary road blocks, or planned lane closures without having to remove the lane from the network.

The selection panel shows the current status of the selected lane and offers a button to toggle between open and closed. Closing or reopening a lane is a local edit just like a speed or permission change and only becomes permanent once the scenario is saved. Reopening a previously closed lane restores its original vClass permissions.

Editing lane connections

At each intersection, SUMO uses explicit lane-to-lane connections to describe which outgoing lane a vehicle may reach from a given incoming lane. These connections control which turns are actually possible, independent of the geometry of the junction.

When a lane is selected, the sidebar lists all of its outgoing connections. From there you can:

• remove individual outgoing connections to forbid a specific turn
• add a new outgoing connection by picking one of the candidate target lanes at the downstream junction

After clicking Add connection, a list of all valid target lanes at the downstream junction appears in the sidebar. Selecting a candidate from this list previews the new connection directly on the map, where it is drawn as a dashed line until the scenario is saved.

Adding or removing a connection changes only the routing topology, not the geometry of the road. As with all other edits, connection changes stay local until you save the scenario. On save, the traffic demand is repaired automatically so that existing routes remain valid under the new connection set.

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.

Rerouting

Open Configuration → Global Rerouting to configure SUMO route recalculation based on recent traffic speeds. The switch controls whether the scenario has a rerouting configuration. On stages a new configuration with SUMO defaults and 100% equipment probability when none exists; switching back to On before saving restores an existing configuration. Off stages its removal. Nothing is written until you choose Save in the top-right toolbar. Switching on does not necessarily activate rerouting during the journey.

The main fields are:

• Rerouting Penetration Rate: the chance of randomly assigning a rerouting device. Enter a value above 0% and at most 100% (including fractions below 1%), or choose × for 0%. The input is replaced by a Disabled (0%) button that shows Click to adjust on hover or focus; adjusting starts again at 100%. Imported configurations using SUMO's special default −1 also show this button. Adjusting and disabling again restores their original −1 value, so no hidden change remains staged. The API continues to use probabilities from 0 to 1 and the special value −1.
• Pre-departure rerouting interval: seconds between route recalculations while waiting to depart (device.rerouting.pre-period in SUMO). The × button sets 0 and shows Disabled (no pre-departure updates); Click to adjust restores an editable field starting at the SUMO default of 60 seconds.
• En-route update interval: seconds between route recalculations during the journey (device.rerouting.period in SUMO). The default 0 disables periodic en-route rerouting even when a configuration exists. The Editor shows Disabled (no updates) for 0; choose Click to adjust to start with 600 seconds (10 minutes), or × to return to 0.

Advanced settings contains:

• Adaptation interval: seconds between updates to routing travel-speed estimates (device.rerouting.adaptation-interval in SUMO). Enter a value above 0, or choose × for 0 and Disabled (No updates). Click to adjust restores the SUMO default of 1 second.
• Averaging method: choose moving average (device.rerouting.adaptation-steps) or exponential averaging (device.rerouting.adaptation-weight). Only the selected method’s input is shown; switching methods takes effect on Save.
• Adaptation steps: whole-number sample count for the moving average (device.rerouting.adaptation-steps in SUMO). The window spans interval × steps seconds. Enter at least 1 step; the SUMO default is 180 steps.
• Adaptation weight: exponential averaging weight above 0 and at most 1 (device.rerouting.adaptation-weight in SUMO). Higher values react more slowly; 1 retains the initial speed estimate. The Editor default is 0.989 when selecting this method; this is distinct from SUMO’s default of 0.
• Mode: SUMO routing flags, default 0. Modes 0–4 select default, aggregated, effort, combined or aggregated/custom routing. Modes 8–12 add the flag to ignore temporary permission changes while routing; vehicles may then wait at closed roads. Mode does not activate periodic rerouting.

Imported adaptation_weight=0 is displayed as Moving average with 180 samples; adaptation_steps=0 is displayed as one sample, which also applies the latest speed without smoothing. These display equivalents do not stage a change. Unrelated edits preserve the original XML values, including an omitted probability option: SUMO treats omission differently from explicitly setting −1 for implicit trip devices.

Times use numeric seconds and may include fractions. Rerouting edits appear in Changes as Changed rerouting properties or Removed rerouting properties. Use the toolbar Save to apply them along with network, signal-plan and demand edits, or Revert to discard them. A rerouting-only Save updates the baseline and scenario version without reloading the network. Another active scenario edit may temporarily lock saving.

Switching Off and saving deletes all scenario-level rerouting options, including additional imported options not shown in the form. Their previous values are not retained. Switching On starts from SUMO defaults with 100% equipment probability again. Before saving, Revert restores the last loaded or saved configuration.

Save submits rerouting, network, signal-plan and demand changes together in one Editor patch. The runner edits the scenario files directly. A successful save updates metadata and increments the version once. If a step fails, an error is shown; some file changes may already have been applied and are not automatically undone. Review the scenario before retrying. Revert only discards local staged edits; it cannot undo file changes made by a failed save.

Imported and built-in settings are read from the scenario configuration. Missing fields use the defaults whenever any rerouting option exists. A configuration's presence alone does not guarantee rerouting during the journey; vehicle assignment, trip definitions and the period also matter. The Workspace API reference lists all seven properties, their corresponding SUMO option names and API examples, including rerouting: null.

Imported exponential averaging settings are displayed and editable under Advanced settings. Switching averaging methods replaces the previous averaging option while retaining the other rerouting settings. Turning rerouting Off and On is not needed to change methods.