Distributed Urban Traffic Simulator
Multi-process distributed traffic simulation engine in Java featuring 10 independent JVM nodes communicating via custom TCP Socket protocols, multi-threaded concurrency, adaptive traffic light policies, dynamic routing algorithms, and a real-time 20 FPS Swing graphics dashboard.
Simulating urban traffic with distributed multi-process nodes.
Developed for the Distributed Systems course at Politécnico do Porto, this platform simulates complex vehicle flows (Motorcycles, Cars, Trucks) across a multi-intersection urban network where system components run as 10 independent OS processes on separate JVMs.
The solution implements client-server TCP socket communication using a custom binary envelope protocol, lock-free concurrent data structures (ConcurrentLinkedQueue, AtomicLong), dedicated traffic light control threads, and a custom Java Swing desktop dashboard rendering real-time map animations at 20 FPS.
Real-time interactive map animation rendered at 20 FPS in Java Swing with live vehicle position tracking
The Problem & Key Challenges
Simulating high-density urban traffic requires coordinating distributed network components without central bottlenecks while accurately tracking vehicle progression, queue formation, and traffic signal cycles.
The system decouples vehicle generation (EntranceProcess), queue & signal processing (IntersectionProcess), destination tracking (ExitProcess), and real-time visualization (Coordinator) across 10 independent processes.
- Coordinating 10 concurrent JVM processes over custom TCP Sockets without message loss or race conditions
- Designing a custom TCP binary serialization envelope supporting 11 distinct event & metric message types
- Implementing real-time adaptive traffic light policies dynamically calculating queue density (AdaptiveDensityPolicy) and wait times (AdaptiveWaitTimePolicy)
- Designing queue-based dynamic vehicle routing algorithms (QueueBasedRoutingPolicy) with live metric cache fallbacks
- Building a 20 FPS custom interactive map animation & analytics dashboard in pure Java Swing (Graphics2D) without external libraries
Architecture & Technical Decisions
Distributed multi-process architecture with 10 independent JVM processes communicating via TCP Sockets using Java object serialization and custom envelope protocols.
- True process isolation: process crashes do not cascade, mimicking real distributed edge nodes
- Asynchronous TCP socket communication prevents blocking vehicle flow between intersections
- Dedicated traffic light control threads ensure precise timing independent of network socket I/O
- Centralized Coordinator aggregates metrics and renders GUI at 20 FPS without altering simulation logic
Tech Stack & Infrastructure
Project Diagrams & Interfaces
Real-time interactive map animation rendered at 20 FPS in Java Swing with live vehicle position tracking
High-level distributed architecture diagram showing 10 JVM processes connected via TCP Sockets
Real-time metrics dashboard displaying live queue sizes, vehicle distribution, and custom Graphics2D charts