Autonomous commercial vehicles from two more startups have completed successful demonstrations on public roads in the United States.

Californian company udelv's autonomous light delivery van made two deliveries to customers of a market in San Mateo.

And Embark, a San Francisco company, completed a coast-to-coast test drive with its autonomous system installed in a Peterbilt tractor unit, towing a semi-trailer 4000 kilometres from Los Angeles to Jacksonville, Florida.

It had a driver supervising all the way, but operated autonomously in all of its freeway running.

The udelv four-wheeler van was also supervised by a safety driver (in accordance with state laws) when it did a four-kilometre delivery run, autonomously negotiating a route that included traffic lights, lane changes, turns across oncoming traffic at uncontrolled intersections and multiple stops and starts.

The custom vehicle has a fully electric powertrain and features 18 secure cargo compartments with automatic doors.

"Customers simply open the locker with a press of a button on their mobile device and the vehicle heads on its way to the next delivery or back to the store," says udelv CEO Daniel Laury.

Such deliveries, he reckons, "are the perfect first application for autonomous vehicles."

A smartphone app will also allow customers to potentially reschedule deliveries and the udelv has developed a system to monitor and control the vehicles remotely and allow for overrides and human-assisted guidance if necessary.

In its current configuration, the udelv vehicle can drive for up to 100 kilometres per cycle and can load up to 317 kilograms (700 pounds) of cargo, udelv says.

Embark says it has so far integrated its autonomous driving systems into five Peterbilts. It has no plans to build its own trucks, but does have plans to install its systems into 40 more tractor units this year, for further testing in long-haul operations.

Co-founder and CEO Alex Rodrigues says its ultimate aim is to have its autonomous systems "drive" the trucks on freeways, with a driver to enter and exit the highways and to drive in urban areas.

This, he says, will not cost truckies their jobs – but will allow them to cover longer distances and make more deliveries in less time.

Rather than "pre-map" a route, as some others in the autonomous vehicle field do, Embark relies on the data from the sensors in its onboard system to map the host truck's surroundings in real-time and avoid obstacles. The system comprises five cameras, three long-range radars and two or more lidars.