Have you ever wondered how traffic simulations can help shape smarter cities? Our latest development, within the scope of the DIDYMOS-XR project, brings an interactive Smart City Digital Twin, to your web browser. This means no downloads and no installations for users, just seamless access to a real-time traffic simulation powered by the technical systems SUMO, Unity 3D, and WebGL.
We developed a high-quality 3D model of a town in Germany called Etteln, mapped its road network using OpenStreetMap (OSM), and integrated SUMO to simulate real-world traffic conditions. SUMO runs in the background via an API, generating vehicles, pedestrians, and public transport, while Unity renders them in a visually rich 3D Digital Twin.
No Installations Needed – Just Open and Simulate!
Traditional traffic simulation software often requires bulky downloads and system configurations. Our web-based application removes this barrier, an approach which offers advantages including:
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- Instant Access: Run the simulation directly in your browser, with no need for specialized hardware or software installation.
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- Cross-Platform Compatibility: Whether you’re on Windows, macOS, or Linux, all you need is a browser.
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- Effortless Updates: Any improvements or bug fixes are deployed instantly, without requiring users to reinstall anything.
By leveraging the graphics interface WebGL, our simulation delivers smooth, interactive 3D visuals without sacrificing performance.
Open-Source and Customizable
We chose SUMO (Simulation of Urban Mobility),developed by DLR in Germany, as the traffic simulation engine because of its flexibility, scalability, and open-source nature. Unlike closed-source solutions, SUMO allows us to:
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- Customize and Modify: Adapt traffic patterns, vehicle behaviors, and road layouts to reflect real-world conditions.
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- Handle Large-Scale Simulations: SUMO efficiently manages thousands of vehicles, making it ideal for city-scale digital twins.
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- Seamlessly Integrate with Unity: Using TraCI (Traffic Control Interface), we synchronize SUMO’s traffic data with our Unity visualization in real time.
Unlike the alternative simulator CARLA, which is resource-intensive and geared toward autonomous driving research, SUMO provides a lightweight yet powerful alternative for large-scale, browser-friendly traffic simulations.
Features That Bring Roads to Life
Our traffic simulation application is also highly customizable, offering a variety of tools to design and manage road networks dynamically. Its functions include:
Advanced Lane Customization:
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- Split and Merge Lanes – Create more realistic road networks with merging and splitting lanes.
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- Block Lanes – Temporarily close roads to simulate construction work or traffic incidents.
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- Dedicated Lanes – Add exclusive lanes for buses, bicycles, and pedestrians.
Custom Traffic Generation:
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- Vehicle Variety – Simulate different vehicle types, including cars, buses, motorcycles, bicycles, and trucks.
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- Adjustable Traffic Density – Control the number of vehicles per kilometer to simulate different congestion levels.
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- Dynamic Traffic Flow – Watch vehicles respond to intersections, signals, and pedestrian crossings in real time.
Realistic Pedestrian and Bike Traffic:
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- Custom Pedestrian Paths – Design sidewalks and pedestrian-only zones.
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- Bicycle-Friendly Roads – Allocate cycling lanes and observe bike traffic behavior.
Real-Time Road Modifications:
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- Modify Road Layouts – Add new intersections, or roundabouts dynamically.
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- Traffic Light Control – Simulate different traffic light timings to test congestion impact.
Lightweight, Efficient, and Scalable
And lastly, our approach ensures smooth performance, even when handling complex urban environments. Our Digital Twin:
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- Runs in the Cloud: SUMO operates on a remote server, sending traffic data to the Unity-powered Digital Twin and keeping the client-side load minimal.
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- Is Optimized for WebGL: Unity efficiently renders 3D environments without requiring high-end GPUs.
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- Is Scalable for Smart Cities: Whether it’s a small town like Etteln or a large metropolis, our system scales effortlessly.
This combination of real-time SUMO traffic generation and Unity 3D visualization offers a realistic, high-performance experience without the overhead of traditional simulation software.
The Future of Traffic Simulation is Here
By combining SUMO, Unity, and WebGL, we’ve created a powerful, accessible, and scalable traffic simulation tool. Urban planners, researchers, and policymakers can now analyze, optimize, and visualize traffic flow in real time, all within a web browser.
Author: Dr.-Ing. Tariqul Islam, Digital Twin Technology
