TL;DR
Blind spot detection (BSD) is a safety system that uses radar or camera sensors mounted on a vehicle's sides and rear to monitor the areas a driver cannot see in the mirrors, then triggers a visual or audible warning when another road user enters that zone during a turn or lane change.
Blind spots are the areas around a vehicle that the driver cannot see directly or through the mirrors. On a passenger car they are small, but on a truck, bus or piece of construction machinery they can hide an entire cyclist or pedestrian. Blind spot detection exists to close that gap.
How to understand the way blind spot detection works
A blind spot detection system watches the danger zones continuously and alerts the driver the moment a hazard appears. The typical chain of events is:
- Sensing. Side and rear-mounted sensors — radar, cameras, or both — scan the blind zones several times per second.
- Processing. An onboard processor or AI module analyses the returns. Radar reads range and closing speed; camera systems with computer vision classify whether the object is a person, a cyclist or a vehicle.
- Warning. When something enters the monitored zone, the system raises a staged warning — usually a light in the mirror or A-pillar, escalating to an audible or haptic alert if the driver signals a turn toward the hazard.
On commercial vehicles the near-side (kerb-side) blind spot is the most dangerous, because that is where cyclists and pedestrians travel and where the driver’s sightline is worst. Regulators recognise this: UN Regulation No. 151 (UN R151) defines the Blind Spot Information System (BSIS) test for the near-side of heavy goods vehicles, and the EU General Safety Regulation (Regulation (EU) 2019/2144) has phased BSIS in as mandatory for new heavy vehicle types from 2022 and all new registrations from 2024.
Radar versus camera detection
There are two dominant sensing technologies, and the right choice depends on the operating environment.
- Radar BSD performs reliably in poor weather and darkness and directly measures how fast an object is closing. Its weakness is that it cannot tell a person from a lamp post.
- Camera BSD with AI classifies road users, so it can suppress false alarms from roadside furniture and raise priority warnings for vulnerable road users. It depends on adequate lighting or infrared illumination at night.
Because each technology covers the other’s weakness, many heavy-vehicle systems fuse radar and AI cameras.
Quick reference: radar vs camera BSD
| Attribute | Radar BSD | Camera BSD (AI) |
|---|---|---|
| Detection range | Up to 30 m rear/side | 3–10 m near-zone |
| Works in darkness | Yes | With IR illumination |
| Works in rain/fog | Yes | Reduced |
| Classifies road users | No | Yes (person vs object) |
| Typical refresh rate | 20–50 Hz | 25–30 fps |
| Best mounted at | Rear corners, sides | Kerb-side, A-pillar view |
Benefits of a blind spot detection system for fleets
- Fewer side-swipe and turning collisions: trucks make up roughly 3–5% of vehicles yet are involved in about 15% of EU road deaths, and vulnerable road users account for around a quarter of truck fatalities — the near-side blind spot is a major factor.
- Regulatory compliance with blind spot information system mandates such as Regulation (EU) 2019/2144 and UN R151 in markets that require them.
- Lower insurance and downtime costs, since a single avoided collision typically outweighs the hardware investment.
- Driver confidence, especially for new drivers manoeuvring 12-metre-plus vehicles in dense urban traffic.
Choosing a system for your vehicles
Match the sensor type to your routes, verify that the warning method suits your cab layout, and confirm the system integrates with any recorder or fleet platform you already run. YUNTOR builds BSD cameras and AI detection terminals on self-developed boards, so the sensing, warning and recording layers work together rather than as bolted-on parts.
Looking for vehicle cameras?
From BSD blind-spot detection to infrared reversing and IP network cameras, YUNTOR vehicle cameras are built on automotive-grade, wide-temperature and anti-vibration housings. AHD/analog compatibility lets you match them to existing displays.