I. Where a Commercial Vehicle Sits
Coaches, trucks, and hazardous-chemicals vehicles carry most road freight and passengers, and they are where crashes cluster. Scheduled coaches, chartered coaches, and hazardous-chemicals trucks — the group Chinese rules call 两客一危, two coach classes and one hazardous class — must carry video and join a government supervision platform. Vehicle video uses several cameras, a 4G or 5G link, ADAS (advanced driver assistance), and DSM (driver status monitoring) for a live view, a warning when the driver is tired or distracted, and a record after a crash. That meets the rule and cuts the crash rate sharply.
The link is the core. Video goes up to the regulator and the company desk, live or on demand. An ADAS or DSM alarm has to arrive in seconds. Device status and position are reported too. One vehicle uses about 2–10 GB a month, so coverage, stability, and the data bill all matter. On the move, switching carriers and living with a weak signal are what keep it online.
II. Market Size and How Far It Has Spread
China's market for commercial-vehicle video was about 8 billion yuan in 2023 and is expected to pass 15 billion yuan by 2027. The mandatory rule has pushed 两客一危 close to 100% penetration. General freight, muck trucks, and ride-hailing keep adding cameras. By 2027, factory-fit plus retrofit on commercial vehicles is expected to pass 60%. ADAS and DSM are spreading from premium models across the range, and the AI functions are becoming standard.
III. Rules and Standards
The Measures for Dynamic Supervision and Management of Road Transport Vehicles require 两客一危 vehicles to carry satellite positioning and video. JT/T 1078, the video communication protocol of the satellite positioning system for road transport vehicles, sets how video is uploaded. GB 7258, Safety Specifications for Motor Vehicles Operating on Roads, sets safety equipment on a commercial vehicle. Cities and provinces add their own video rules for muck trucks and ride-hailing.
IV. The Numbers, and Three Fleets
The numbers: a vehicle usually has 4–8 cameras (forward, cab, cargo). Live 1080p needs about 8–32 Mbps. Uploading on an event, or sending a thumbnail, cuts the data, to about 2–10 GB a vehicle a month. An ADAS or DSM alarm has to reach the desk in under 3 seconds. The network changes often on the road. A smart switch across carriers and APNs keeps the online rate above 98%.
A province's 两客一危 desk: more than 20,000 vehicles send video to the supervision platform, for a live spot check, an event alarm, and a look back after a crash. The transport crash rate fell by about 35% year on year.
A courier's line-haul fleet: more than 5,000 trucks carry ADAS and DSM. Fatigue and distraction alarms go to fleet management. The crash rate fell by about 40%, and insurance disputes fell with it.
A city's muck trucks: video and position are online. Illegal dumping, overload, and a run on a banned road are recognized and alarmed on their own. Enforcement got faster, and complaints fell by about 50%.
V. Terms
ADAS (advanced driver assistance): forward-collision warning, lane-departure warning, and the rest. The alarm can be reported over the network.
DSM (driver status monitoring): fatigue, distraction, smoking, a phone call. It alarms on its own and pushes the event to the monitoring desk.
两客一危: scheduled coaches, chartered coaches, and hazardous-chemicals trucks. They must carry video and join a government platform.
VI. What a Cab Without a Camera Misses
6.1 A tired driver
Fatigue and distraction are the main causes of these crashes. A person cannot watch every cab. ADAS and DSM recognize the event and alarm as it happens. The crash rate can fall by 30%–50%.
6.2 A platform the regulator cannot see
两客一危 video has to reach the government platform, and the company needs its own desk. The upload has to hold, and the device has to be online to be checked. The IoT link is what compliance stands on.
6.3 A crash with no picture
After a crash the video has to be pulled to reconstruct what happened. It is stored on the vehicle and backed up in the cloud, and it can be opened from a distance. Several streams — forward, cab, cargo — need a wide pipe back.
VII. Where the Link Is Used
7.1 The live picture
Several cameras go up over 4G or 5G, live or on demand. The desk can preview, play back, and open a clip from a distance. That serves the regulator and the company's own safety desk.
7.2 The alarm
Forward collision, lane departure, fatigue, and distraction are pushed to the desk and the driver in seconds. The alarm is kept, for the later analysis and for who was at fault.
7.3 The vehicle itself
Online status, faults, and position are reported. Fused with CAN data, that supports fuel use, mileage, and how the vehicle was driven.
VIII. Where It Is Heading
AI that acts before the crash. Behavior recognition and a prediction of dangerous driving move the system from a look-back after the event to a warning before it.
5G and the edge. 5G's bandwidth carries several high-definition streams live. Edge computing cuts delay and saves data.
The vehicle and the roadside. The onboard unit talks to roadside equipment, for connected driving and autonomous driving.
IX. Summary
Vehicle video uploads the picture, raises ADAS and DSM alarms, and manages the device. It meets the 两客一危 rule, and the crash rate can fall by 30%–50%. A vehicle uses 2–10 GB a month, and a stable link on the move is what the whole thing depends on.
SimtoLink supplies automotive-grade 4G and 5G IoT SIM cards and modules for this work: a smart switch across carriers, heat, cold, and vibration, so the device stays legal and stays online.