Traffic monitoring systems: Radar-vision fusion explained

Traffic monitoring systems are the silent sentinels of the roads, ensuring the safety and efficiency of the transportation networks. However, environmental challenges such as fog, heavy rain, dust storms, and even glare from the sun can hinder their effectiveness.

Although standalone radar technology can operate in these environmental challenges, it lacks the ability to provide the detailed visual context which is so important for comprehensive traffic management. In this blog, they explore a solution that bridges this gap – the fusion of radar vision technologies.

Traffic safety and monitoring

Imagine a busy highway enveloped in thick fog. Cameras operating in the visible spectrum strain for clarity while the dense mist blankets the view, disrupting the flow of traffic information. Harsh weather such as fog, rain, snow, and dust storms, often affects the efficacy of traffic video monitoring systems in this way.

Adverse weather conditions are a factor in nearly 21% of annual vehicle crashes in the United States 

According to statistics from the Federal Highway Administration (NHTSA), adverse weather conditions are a factor in nearly 21% of annual vehicle crashes in the United States. This highlights the challenge these environmental factors present for traffic safety and monitoring. To help address this, there is a strong demand from traffic management professionals for more advanced monitoring solutions that can somehow ‘see’ through the fog, snow and rain.

Millimetre waves: unveiling the invisible

Until now, the primary technology that can be used in such circumstances is millimetre wave radar. Millimetre waves occupy a unique position on the electromagnetic spectrum. Occupying the frequency range of 30-300 GHz, they are positioned between microwaves and infrared waves. Their shorter wavelengths offer advantages such as higher resolution, stronger anti-interference capabilities, and better penetration through smoke and dust. These attributes make them well-suited for consistent and clear monitoring in various environmental conditions.

Millimetre wave radar functions round-the-clock, unaffected by the weather

This technology has many advantages for traffic control systems. Millimetre wave radar functions round-the-clock, unaffected by the weather. Such systems can be relied upon to deliver precise measurements of speed and the direction of objects. They can also track objects over long distances with remarkable accuracy.

Yet radar has one important drawback: it lacks the capacity to visualise. As a result, it cannot perceive and monitor detailed information about the target, such as the colour of the vehicle or its licence plate – information that is often essential in incident management and reporting. This is where the fusion of radar with robust imagery taken from a video input can become so powerful. Robust imagery can compensate for the non-visualization of radar.

Radar-video fusion: bridging the gap

The fusion technique pairs radar range perception with video visual perception. To achieve this, AI-based algorithms merge two different coordinate systems to enrich target information, blending the strengths of both sensing methods. The radar aspect excels in tracking multiple objects beyond the horizon with a wide detection range and high precision. It provides valuable insights even under adverse weather conditions. The video components, meanwhile, offer the advantage of visualisation—allowing for structured analysis of the traffic scene.

The fusion technique pairs radar range perception with video-visual perception

The fusion of technologies creates a fail-safe system where the weaknesses of one are fortified by the strengths of the other. The result? A traffic monitoring system that ensures uninterrupted, comprehensive, and reliable data, even in harsh weather conditions. Cities that implement radar-video fusion technology showcase the advancements in smart urban planning. With this technology, traffic management departments can optimise traffic flow and digitise highway and urban roads.

Integration of radar technology

Furthermore, the fusion technology contributes to promoting road safety by enabling early detection and warning of potential hazards in challenging situations including curved roads, blind spots at intersections, and obstacles outside the visual range.

Adopting radar-video fusion is one more step towards more sustainable traffic management. Through the growing integration of radar technology, which is less affected by environmental conditions, cities can reduce their reliance on intense lighting required by vision systems to function in low-light situations. This progress contributes to the realisation of a sustainable urban infrastructure.

Explore Hikvision’s radar-video fusion cameras

Hikvision has incorporated the radar-video fusion technology in a series of traffic cameras including the Incident Detection Radar-Video Fusion Camera, the All-Rounder Checkpoint Camera, the All-Rounder Intersection Violation Camera, and the Radar-Video Fusion Smart Monitoring Camera.