The company is in a three-way partnership with the truck-leasing company Ryder and the appliance giant Electrolux, known best for its line of Frigidaire appliances.
Embark has taken an existing truck and equipped it with a series of sensors and software, to navigate stretches of highway, but would still require human drivers to enter and exit highways and drive on city streets.
The cross-country trek, first reported by TechCrunch, took five days, which the company said it thinks it could get down to two days.
During the entirety of the test a human driver was seated behind the wheel at all times to take control of the truck if necessary, though company CEO Alex Rodrigues told TechCrunch the truck was drive autonomously for "the vast majority" of the time.
Embark started delivering refrigerators along a 650-mile stretch of Interstate 10 from El Paso, Texas, to Ontario, Calif., in October.
Those trucks were driven with Level 2 automation, a federal standard that denotes the ability of the vehicle to steer itself as well as accelerate and brake under normal conditions.
A driver is required to pay attention to the road at all times and take control if the system is unable to navigate a hazard, and the driver is in the driver's seat at all times.
"We are trying to get self-driving technology out on the road as fast as possible," Rodrigues told The New York Times in November. "Trucking needs self-driving and self-driving needs trucking."
In a promotional video on the company's website, Rodrigues said Embark is planning on additional testing on new freight routes in the near future as it continues to test out the system and prepare for a market launch.
According to a January report from CB Insights, driverless automobiles will reduce demand for truckers, taxi drivers and other driving professionals.
Instead, telematics technology -- the use of telecommunications to facilitate communication and gather data from vehicles -- will allow taxi and trucking companies to manage their self-driving fleets so that they provide services and run their routes with optimal efficiency, but humans will still be needed to manage these systems.
Driverless trucks are being used to move iron ore at mines in Australia, and the Canadian energy company Suncor Energy is working to automate its own trucks in a process its CFO estimates will take 800 human drivers off its drilling site.
Max Fuller, executive chairman of US Xpress, the fourth-largest trucking company in the US, told Trucks.com in July 2017 that he believes long-haul trucks will have Level 4 autonomous capability in three to four years.
"We're trying to enhance the safety, give [drivers] the ability to be more productive, try to create a better return for the company and supply a better service for our customers," he said. "Our number one goal is to create jobs that people want and that's the reason we need products that make the job a lot simpler for drivers."
— Nathan Eddy is a filmmaker and freelance journalist based in Berlin. Follow him on Twitter @dropdeaded209_LR.