[Paper Review] Intelligent Transportation Systems Using External Infrastructure: A Literature Survey

Christian Creß, Zhenshan Bing+1 more|arXiv (Cornell University)|Dec 10, 2021

Traffic Prediction and Management Techniques65 references17 citations

TL;DR

This paper presents a systematic literature review of intelligent transportation systems (ITS) using external infrastructure, analyzing 357 papers and 52 test beds from 2009 to present. It identifies trends in sensor technology, software architecture, and value-added services, concluding that future ITS development must prioritize reliable perception, plug-and-play integration, and secure, decentralized real-time distribution of digital twins for scalable, safe, and autonomous traffic systems.

ABSTRACT

The main problems in transportation are accidents, increasingly slow traffic flow, and pollution. An intelligent transportation system (ITS) using external infrastructure can overcome these problems. For this reason, the number of such systems is increasing dramatically, and therefore requires an adequate overview. To the best of our knowledge, no current systematic review of existing ITS solutions exists. To fill this knowledge gap, our paper provides an overview of existing ITS that use external infrastructure worldwide. Accordingly, this paper addresses current questions and challenges. For this purpose, we performed a literature review of documents that describe existing ITS solutions from 2009 until today. We categorized the results according to technology levels and analyzed its hardware system setup and value-added contributions. In doing so, we made the ITS solutions comparable and highlighted past development alongside current trends. We analyzed more than 357 papers, including 52 test bed projects. In summary, current ITSs can deliver accurate information about individuals in traffic situations in real-time. However, further research into ITS should focus on more reliable perception of the traffic using modern sensors, plug-and-play mechanisms, and secure real-time distribution of the digital twins in a decentralized manner. By addressing these topics, the development of intelligent transportation systems will be able to take a step towards its comprehensive roll-out.

Motivation & Objective

• To address the lack of a comprehensive, systematic review of ITS using external infrastructure, particularly focusing on hardware, software, and value-added contributions.
• To analyze the evolution of ITS from early systems to modern digital twin-based architectures, highlighting technological advancements and functional shifts.
• To identify open research challenges in reliability, scalability, and cybersecurity for large-scale deployment of ITS.
• To compare and categorize 52 test bed projects globally based on sensor configurations, system functionalities, and technological maturity.
• To guide future research by identifying key priorities such as secure decentralized data distribution, plug-and-play mechanisms, and robust perception systems.

Proposed method

• Conducted a systematic literature review of peer-reviewed papers and technical documents on ITS using external infrastructure from 2009 to 2023.
• Applied filtering criteria to include only systems with external infrastructure (e.g., RSUs, sensors, control units) and excluded purely vehicle-based or simulation-only studies.
• Categorized systems by technology level, sensor types (e.g., radar, LiDAR, cameras), and software features (e.g., V2X, digital twins, platooning).
• Extracted and analyzed hardware configurations and software functionalities to assess system capabilities and value-added services.
• Mapped trends in sensor deployment and software evolution across regions (North America, Europe, Asia) and test bed projects.
• Evaluated non-functional requirements such as real-time performance, scalability, and cybersecurity, particularly in distributed and edge-computing architectures.

Experimental results

Research questions

• RQ1 How have the technological capabilities and sensor configurations of ITS using external infrastructure evolved from 2009 to 2023?
• RQ2 What are the key value-added services provided by modern ITS, and how do they differ across regions and test bed projects?
• RQ3 What are the main challenges in ensuring reliability, scalability, and security—especially in decentralized and real-time digital twin systems—within ITS?
• RQ4 To what extent have existing test beds implemented secure communication, real-time data distribution, and self-healing mechanisms?
• RQ5 What are the open research gaps in enabling a nationwide, secure, and scalable rollout of ITS using external infrastructure?

Key findings

• Current ITS can deliver highly accurate, real-time information about individual traffic participants using advanced sensor fusion and V2X communication.
• The number of ITS projects using external infrastructure has grown significantly, with 52 test bed projects identified globally, primarily in North America, Europe, and Asia.
• Digital twin technology is emerging as a key enabler, but real-time, secure, and decentralized distribution of high-fidelity digital twins remains an open challenge.
• Cybersecurity remains a critical vulnerability, with many systems still using unencrypted communication; only a few test beds (e.g., InterCor, SCOOP@F) have implemented advanced security mechanisms like blockchain or zero-trust protocols.
• Centralized cloud-based architectures are limited by scalability, energy efficiency, and failure tolerance; distributed and edge-computing approaches are gaining traction but require further validation in high-data-density environments.
• Future ITS development must prioritize reliable perception using modern sensors, plug-and-play integration, and secure, decentralized real-time data distribution to enable large-scale deployment.