(TNS) -- Did Daimler take a self-driving truck for a spin in Oregon late last year? Not really.
As Willamette Week reported Wednesday, Daimler Trucks North America notified the state late last year it would be testing a truck with automated features on Interstate 84.
The test, which occurred in broad daylight on a December weekday, used technology akin to adaptive cruise control, a feature available in many new consumer cars that matches the speed of the next vehicle ahead.
DTNA, which has its headquarters on Portland's Swan Island, was exploring a technology called "platooning," in which two or more trucks follow one another closely together to reduce wind resistance and save fuel.
Sensors and vehicle-to-vehicle wireless communication help the second truck maintain a certain distance from the truck ahead -- much closer than would be safe if it were up to a human driver to react.
If the first truck stops short to avoid a collision, it would nearly instantly transmit that to the following truck, and the second truck would automatically apply the brakes before its human driver could realize what's happening.
Steering, however, is left to the driver. It's considered "Level 1" autonomy on a five-level scale by the engineers organization SAE International and the National Highway Traffic Safety Administration.
Tesla cars equipped with Autopilot software use more advanced automation. Those vehicles can both steer and control acceleration.
DTNA is testing autonomous big-rigs in Nevada, which explicitly allows testing self-driving cars.
But the platooning test occurred in Oregon because I-84 has become a standard route for testing fuel economy, company officials said.
"If we want to compare any result we had here with past results, we understand the route, we understand the speed, we understand the terrain," said Derek Rotz, DTNA's director of advanced engineering. "It gives us the best sort of apples-to-apples comparison.
The test is fully legal under Oregon law, and Daimler wasn't required to notify the state transportation department.
Nor would it, or any other company, necessarily have to alert the state if it were testing a fully autonomous vehicle.
"As long as they're in compliance with Oregon law, which at this point is silent on autonomous vehicles, then they could do it," said Andrew Dick, the state transportation department's adviser on connected, automated and electric vehicles.
ODOT won't say whether it would be legal to test a truly driverless car - meaning no human in the driver's seat - in the state because there's been no legal determination.
But in a 2014 legal analysis published in the Texas A&M Law Review, Bryant Walker Smith, an assistant professor at the University of South Carolina, argued that they're probably legal in all 50 states because they assume -- but don't require -- the presence of a human driver.
Some states have since adopted more specific laws, but Oregon has not. Two bills proposed this year in the Oregon Legislature would have created a regulatory framework, but each is dead in committee after missing key deadlines.
DTNA said it plans to continue its platooning tests in Oregon, and that it will continue to notify the state in advance.
If it hasn't occurred yet, it might not be long before Oregon does become a testing site for self-driving vehicles.
Portland Mayor Ted Wheeler said earlier this month that the city was "open for business" to companies developing autonomous vehicles. He and Commissioner Dan Saltzman directed the city's transportation bureau to develop policies to give such companies a path to testing the vehicles on city roads.
©2017 The Oregonian (Portland, Ore.) Distributed by Tribune Content Agency, LLC.