Quick Answer
sumo.exe is safe. SUMO (Simulation of Urban Mobility) is an open-source traffic simulator. sumo.exe runs core simulation, GUI, and I/O components in separate processes to improve stability and prevent cross‑process interference.
Is it a Virus?
NO - Safe
Must be in C:\Program Files\SUMO\bin\sumo.exe or C:\Program Files\SUMO\sumo.exe
Warning
Multiple sumo processes are normal
SUMO uses separate processes for core, GUI, and rendering; high counts may indicate active simulation with GUI or headless mode
Can I Disable?
YES
Close SUMO via GUI or end the sumo.exe process in Task Manager; you can also run in headless mode to save resources
What is sumo.exe?
sumo.exe is the Windows executable for the SUMO (Simulation of Urban Mobility) traffic simulation toolkit. When you run a SUMO project, sumo.exe launches to perform the core simulation, reading network data, vehicle routes, and traffic signals, while separate components may render the GUI or handle I/O tasks.
SUMO uses a modular, multi-process architecture: a central simulation core, GUI/visualization tasks, and data I/O. This separation improves stability and enables headless batch runs.
Quick Fact: SUMO began as a research tool and remains active as an open-source project. The sumo.exe process typically works with sumo-gui for visualization or in pure headless mode for batch simulations.
Types of SUMO Processes
- Simulation Core Process: Executes vehicle movements, network dynamics, and time steps
- GUI Process: User interface for configuring networks and viewing results
- Renderer/Visualization Process: Renders visual output when using sumo-gui
- Input/Output Process: Handles file I/O for networks, routes, and results
- Preprocessor/Translator: Converts network and route data into SUMO-ready formats
- Utility/Logging Process: Background tasks, logging, and telemetry
Is sumo.exe Safe?
Yes, sumo.exe is safe when it originates from the official SUMO project and is obtained from trusted sources (sumo.city.ac.uk or the official SUMO repositories).
Is sumo.exe a Virus or Malware?
The real sumo.exe is NOT a virus. Malware may mimic names; verify with location, signature, and source.
How to Tell if sumo.exe is Legitimate or Malware
- File Location: Must be in
C:\Program Files\SUMO\bin\sumo.exe or C:\Program Files\SUMO\sumo.exe. Any other path is suspicious.
- Digital Signature: Right-click the file in Explorer → Properties → Digital Signatures. Should show a signature from "SUMO Project" or an official signer.
- Resource Usage: Typical SUMO CPU usage varies by simulation; excessive sustained usage when idle is suspicious.
- Behavior: SUMO should run when you start a project. If you see sumo.exe running without a SUMO project, scan for malware.
Red Flags: Unexpected sumo.exe locations (like Temp or AppData), lack of a valid digital signature, or constant high resource usage outside of a running SUMO simulation warrant a malware scan.
Why Is sumo.exe Running on My PC?
sumo.exe runs when you start a SUMO project, or when a GUI or headless batch job initiates a simulation. It may also stay active to monitor results after a run.
Reasons it's running:
- Active Simulation: You're actively running a SUMO model; the core process updates vehicle states in real time.
- GUI or Visualization: sumo-gui or visualization components run alongside for live inspection of results.
- Headless/Batch Runs: Automated experiments keep sumo.exe alive to finish simulations and write outputs.
- Background Data Sync: Some setups keep SUMO data synchronized with repositories or dashboards during runs.
- Post-Processing: Analysis tools and scripts may keep a process open to generate reports after a run.
Can I Disable or Remove sumo.exe?
Yes, you can disable sumo.exe. If you don't need SUMO, uninstall or remove the sumo package or simply stop and disable the corresponding service or startup entry.
How to Stop sumo.exe
- End Active Run: In the GUI, click Stop; in batch mode, terminate the process via Task Manager.
- Close GUI: Close the sumo-gui window or exit the GUI launcher.
- Terminate Process: Open Windows Task Manager (Ctrl+Shift+Esc), locate sumo.exe, right-click -> End Task
- Prevent Startup: Disable any startup shortcut or service that launches SUMO automatically
- Verify No Background Jobs: Ensure there are no residual batch jobs or scripts invoking SUMO in the background
How to Uninstall SUMO
- ✔ Windows Settings -> Apps -> Apps & Features -> SUMO -> Uninstall
- ✔ Control Panel -> Programs -> Uninstall a program -> SUMO -> Uninstall
- ✔ If installed via a package manager, use the appropriate command to remove SUMO
Common Problems: High CPU or Memory Usage
If sumo.exe is consuming excessive resources during a run or idle time:
Common Causes & Solutions
- Large network or complex scenario: Reduce network size or simplify the scenario; monitor with SUMO's built-in stats.
- Edge-case routing or dynamic traveler logic: Review route definitions and disable heavy dynamic features if unnecessary.
- GUI rendering while idle: Close or minimize the GUI; use headless mode for long-running experiments.
- Extensions or external scripts: Disable or remove third-party tools that hook into SUMO.
- Outdated SUMO: Update SUMO to the latest release to fix performance regressions.
- Insufficient hardware resources: Increase RAM or CPU budget, or run on a machine with better specs.
Quick Fixes:
1. Close unnecessary SUMO windows and reduce scenario complexity
2. Run in headless mode to save resources; use sumo for batch mode
3. Check logs in C:\Users\Public\Documents\SUMO\logs for warnings
4. Update to the latest SUMO version
5. Limit GUI rendering by starting in non-GUI mode
Frequently Asked Questions
Is sumo.exe a virus?
No, the legitimate sumo.exe from the SUMO project is not a virus. Ensure it resides in C:\Program Files\SUMO\bin\sumo.exe and has a valid digital signature from an official SUMO signer.
Why is sumo.exe using so much CPU?
High CPU usage typically occurs during complex network simulations or graphical rendering. Use the GUI Task Manager to identify stages; consider running in headless mode during heavy workloads.
Can I delete sumo.exe?
Yes, you can uninstall SUMO from Windows Settings -> Apps. Your simulations and data will be removed unless backed up; reinstalling is possible from the SUMO project website or repository.
Can I disable sumo.exe?
Yes, you can close the GUI, stop the batch run, or disable startup items. For no background activity, run SUMO only when needed.
Why does SUMO open at startup?
SUMO is usually not set to start automatically by default. If you see sumo.exe at startup, disable the shortcut or service that launches it.
How can I reduce SUMO's memory usage?
Disable unnecessary features, reduce network size, upgrade hardware, and run in headless mode to minimize memory footprint.