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Digital Twin for Smart Intersections 🚦 The Future of Traffic Management

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A real-time Digital Twin platform merges LiDAR sensing with simulation to optimize intersections, enhance safety, and cut congestion.

Published August 11, 2025 By EngiSphere Research Editors
Illustration of Deploting Digital Twin in Intersection Traffic Management © AI Illustration
Illustration of Deploting Digital Twin in Intersection Traffic Management © AI Illustration

TL;DR

A real-time Digital Twin platform using LiDAR and VISSIM accurately mirrors and optimizes intersection traffic, enabling smarter, safer, and data-driven traffic management.

The R&D

🌆 Why Our Intersections Need a Makeover

If you’ve ever been stuck at a red light with no cars coming from the other side, you’ve witnessed inefficiency in action. Intersections are the beating hearts of urban traffic networks — and also hotspots for congestion, accidents, and frustration.

Traditionally, city engineers have relied on manual counts, cameras, and simplified simulations to understand and improve intersection performance. But these methods come with big drawbacks:

❌ Cameras struggle in bad weather or at night.
❌ Manual counts are slow and prone to errors.
❌ Simulations often rely on outdated data, missing real-time dynamics.

This is where Digital Twin technology comes in — a high-tech, real-time, and data-rich approach to making our roads smarter and safer.

🖥️ What’s a Digital Twin, Anyway?

A Digital Twin is a virtual replica of a real-world system that updates continuously with live data. NASA first used the term to describe detailed simulations of spacecraft, and today, industries from manufacturing to healthcare are adopting it.

In transportation, a Digital Twin can:

  • Mirror roads, intersections, and vehicles in a simulation.
  • Update instantly using sensor data from the real world.
  • Test "what-if" scenarios without disrupting traffic.
  • Predict and prevent congestion before it happens.

Think of it as a living model of the city’s traffic — one that never sleeps, never guesses, and never ignores changing conditions.

📡 The Research Breakthrough: Real-Time Intersection Digital Twin

A team at New Jersey Institute of Technology (NJIT) has created a real-time Digital Twin platform for traffic intersections. It combines:

  1. High-resolution LiDAR sensors to capture live traffic data.
  2. VISSIM microsimulation software to model traffic behavior.
  3. Genetic algorithms to fine-tune simulation accuracy.

The goal? Monitor, evaluate, and optimize intersections in real-time — making decisions based on facts, not forecasts from last year.

🔍 How It Works

Here’s the step-by-step magic:

1. LiDAR Data Collection 📡
  • A single LiDAR sensor scans the intersection in 360° with a 200m range.
  • It detects every vehicle, pedestrian, bus, or cyclist — day or night, rain or shine.
  • The BlueCity AI system classifies objects and tracks their speed, position, and dimensions every 0.1 seconds.
2. Data Transformation 🔄
  • The system converts LiDAR coordinates into VISSIM’s simulation format using a Python algorithm.
  • Each detected road user is placed in the correct lane and position in the simulation.
3. Real-Time Digital Twin 🖥️
  • VISSIM displays an exact replica of the intersection, moving in sync with reality.
  • Engineers can view live performance metrics: queue lengths, travel times, lane changes, and even emissions.
4. Model Calibration 🛠️
  • The Digital Twin isn’t just for display — it improves itself.
  • The team used a Genetic Algorithm to adjust VISSIM’s driving behavior parameters until simulated trajectories matched real LiDAR ones.

Result? A 29.8% reduction in trajectory error, meaning the simulation became far more accurate.

🚦 Real-World Testing at NJIT

The researchers tested their platform at the Warren and Lock Street intersection near NJIT’s campus:

  • Duration: 75 minutes during weekday afternoon peak.
  • Vehicles monitored: 1,881.
  • Data resolution: 0.1-second intervals.

Key findings:

  • Average delay per vehicle: 2.61 seconds.
  • Average speed: 46.4 km/h.
  • Maximum queue length: ~30 m (northbound).
  • Total stops: only 196 across all vehicles.

The Surrogate Safety Assessment Model (SSAM) also analyzed potential conflicts, detecting 131 instances (mostly rear-end situations).

🧠 Why This Matters

This Digital Twin approach leapfrogs traditional methods:

FeatureOld WayDigital Twin Way
DataManual counts or camera feedsHigh-resolution LiDAR, 24/7
AccuracyDependent on visibility & human errorAll-weather, centimeter-level
SimulationStatic, based on historical dataDynamic, synced in real-time
CalibrationTime-consuming & manualAutomated via AI
ApplicationsLimited to observationPrediction, testing, optimization

In short, it’s not just seeing the present — it’s predicting and shaping the future of traffic flow.

🔭 Future Prospects

The study’s authors see this as just the beginning. Here’s what could be next:

  1. City-Wide Deployment 🏙️ Multiple LiDAR units could create a network of Digital Twins for every major intersection.
  2. Multimodal Expansion 🚴‍♀️🛴 Adding detailed models for cyclists, scooters, and pedestrians to improve safety for vulnerable road users.
  3. Incident Response 🚓 Detecting crashes or sudden congestion and instantly adjusting signal timing.
  4. Predictive Traffic Management 📊 Running "what-if" scenarios in the background — for example, testing the effect of road closures or events.
  5. Integration with Smart Cities 🌐 Linking Digital Twins to public transport schedules, weather forecasts, and emergency services.
⚠️ Challenges Ahead

No technology is perfect, and the researchers acknowledge hurdles:

  • Occlusion issues: Large vehicles can temporarily block smaller ones from LiDAR view.
  • Data privacy: While LiDAR doesn’t capture identifiable images, strict protocols are needed.
  • Scaling costs: LiDAR and simulation software are powerful but not cheap.

Still, these are solvable problems — and the benefits could far outweigh the costs for busy urban areas.

💡 Final Take

This NJIT project shows how Digital Twin + LiDAR + AI can transform urban traffic from a reactive system into a proactive, self-improving network.

It’s like giving the city’s intersections a brain, a memory, and the ability to learn from every passing car. As smart cities evolve, such platforms could make our commutes shorter, our roads safer, and our air cleaner.

The future of traffic isn’t just about more lanes — it’s about smarter intersections. And with Digital Twins, that future is already pulling up to the stop line. 🚦✨


Concepts to Know

Digital Twin 🖥️ A virtual copy of a real-world system (like an intersection) that updates with live data so you can monitor, test, and improve it in real time. - More about this concept in the article "Digital Twins Tech 🧱 Reinvents Dike Safety".

LiDAR 📡 A laser-based sensor that scans the environment in 3D, measuring distances very accurately — works day, night, and in bad weather. - More about this concept in the article "Can Self-Driving Cars Handle Long Expressway Tunnels? 🚗".

VISSIM 🚗💻 Specialized traffic simulation software that models how vehicles and pedestrians move, letting engineers test changes without touching the real road.

Genetic Algorithm 🧬 An AI-inspired optimization method that mimics natural selection theory to find the best solution to a problem — in this case, fine-tuning traffic models. - More about this concept in the article "Revolutionizing Heating Systems 🏢 🌡️ How Predictive Control is Saving Energy in Commercial Buildings".

Traffic Microsimulation 🛣️ A detailed computer model that simulates the movement of individual vehicles, giving a close-up view of traffic patterns.

Calibration ⚙️ The process of adjusting a model so its results match real-world observations — like tuning a car engine for optimal performance.

Intersection Performance 🚦 A measure of how well an intersection handles traffic, considering delays, congestion, and safety.

SSAM (Surrogate Safety Assessment Model) 🛑 A tool that uses traffic simulation data to detect and analyze potential crash risks before they happen.


Source: Afshari, A.; Lee, J.; Besenski, D. A Digital Twin Platform for Real-Time Intersection Traffic Monitoring, Performance Evaluation, and Calibration. Infrastructures 2025, 10, 204. https://doi.org/10.3390/infrastructures10080204

From: New Jersey Institute of Technology.

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