China's L4 autonomous trucks (full self-driving within a defined area, no human backup required) are finding paying work in factory yards, not on highways

It's 2 a.m. on a factory apron in eastern China. A 4-ton truck rolls up to a loading dock with no one in the cab, no idle engine noise, no driver door. The dock worker scans a manifest. The truck reverses into position. The night's last inter-yard load is done before the shift clocks out.

That scene, still rare and still small, is the first real beachhead for L4 autonomous trucking, and it isn't on the highway. [L4 is shorthand for "Level 4," a Society of Automotive Engineers designation for full self-driving inside a defined area, with no human backup required.] The L4 cargo story, after a decade of demos and small last-mile pilots, is being written first inside factory grounds, industrial parks, and the loading aprons of large warehouses, where routes are fixed, traffic is predictable, and the regulatory perimeter is a fence.

The latest anchor instance is the Z20, a 4.2-ton-rated autonomous light truck co-developed by the self-driving company Zelos (九识) and commercial-vehicle maker Yutong (宇通), according to the Chinese tech publication 量子位 (QbitAI). The Z20 carries a 4.2 metric-ton payload into a 19.32-cubic-meter cargo box on a chassis with a 6,950-kilogram gross vehicle mass, large enough to swallow six to eight standard pallets in a single run. A long-range battery option delivers up to 320 kilometers of unloaded range on a 77.28 kWh pack and supports 400-volt DC fast charging, with a 30-to-80 percent top-up taking roughly half an hour. The standard 43.47 kWh pack recovers about half its charge in the same window.

The specifications matter less than the deployment map. Zelos and Yutong have pitched the Z20 at high-frequency internal transport inside factory yards, industrial parks, and large logistics hubs, the work that sits between a finished-goods line and a long-haul truck, rather than at the curbside drop-offs that defined the previous generation of small autonomous delivery vehicles, often called RoboVans. Zelos, which has deployed more than 25,000 RoboVans across 300 cities and 20 countries and logged over 170 million kilometers of cumulative L4 operations, is using the Z20 to enter the 4-ton light-truck segment for the first time. The structure of the partnership, with Zelos supplying the full L4 stack (perception, planning, control, fleet dispatch) and Yutong building the chassis, manufacturing, and quality control, mirrors the "HI" or Huawei Inside model that Huawei has used in passenger EVs. Zelos calls it "Zelos Inside."

Industrial-park autonomy is a different economic bet from open-road highway trucking for three reasons. The routes are short, fixed, and surveyed in advance, so the perception and planning problem is closer to a tram line than a freeway merge. The vehicle never leaves a fenced, permitted site, so the regulatory exposure is to the site operator, not the public road authority. And the unit economics compete against a human-driven yard truck doing the same back-and-forth at 2 a.m., where the labor premium, the shift differential, and the idling cost are already punishing the operator's P&L.

Zelos and Yutong are not alone. In April 2026, Pony.ai partnered with battery maker CATL to release its own L4 light truck, covered by Guangming Daily and Xinhua, a vehicle designed to span both intercity line-haul and urban distribution rather than only yard duty. In August, Pony.ai unveiled its fourth-generation autonomous heavy truck and a 1,000-unit operating target over the next three years, per Sina Finance. Three near-simultaneous 2026 programs, two from Pony.ai and one from the Zelos and Yutong partnership, suggest the L4 cargo industry is rotating its center of gravity from the sidewalk and the curb to the industrial park.

Zelos's claim that the Z20 is the "largest cargo space and highest payload of any mass-produced autonomous vehicle today" is a vendor framing, and it has not been benchmarked against the Pony.ai plus CATL light-truck spec sheet, which has not been published in the same detail. The source material does not name a first paying customer, does not disclose how many Z20 units are already in revenue service versus on order, and offers no third-party test of the 320-kilometer range or the 30-minute fast-charge figure. The "4.2 tons equals 40 refrigerators" comparison that recurs in Chinese trade press is marketing math, and the analogy does not survive contact with a logistics manager who cares about pallets per shift, not payload in domestic units.

The watch item, then, is the first Z20 fleet operator that publishes a shift report: how many loads per night, what the dispatch latency looks like, how the truck behaves when a pedestrian steps into the lane at 2 a.m. and the perception stack has to make the call. The 2 a.m. factory scene is the right place for L4 cargo to start. What the same stack proves on the open road, and on what timetable, is the next test.