Most 18-wheelers need a human driver to go anywhere. But at Riggy’s Truck Parking in Katy, a self-driving truck drove over speed bumps and passed through an exit gate Tuesday for a demonstration in which the driver was just along for the ride.

John Nelson, who has more than 30 years of truck driving experience, sat in the driver’s seat with his hands hovering over the steering wheel and his feet near the gas pedal and brakes. As a safety driver, his job is to watch the area while the truck is moving and be ready in case anything goes wrong.

“I'm constantly scanning to make sure the truck is seeing what I visually see, anticipating how it's going to react to what's going on around me,” Nelson told the Houston Chronicle before the start of the demonstration route.

Bot Auto, a Houston-based autonomous trucking company, has been conducting full driverless testing with a safety driver present since last fall. This year, the company plans to launch its West Houston to East San Antonio route without a driver on Interstate 10.

“I wanted to build something because I'm a technologist. I wanted to build something and create value out of it,” Bot Auto Founder and CEO Xiaodi Hou said.

The company is currently partnering with Steves & Sons, a woodworking company, for driverless deliveries.

On Tuesday, one of its autonomous vehicles took a Chronicle reporter on a shorter route — less than an hour — starting at Riggy’s Truck Parking, traveling onto Interstate 10, getting off at exit 725 near Sealy and returning.

What is it like riding in a self-driving truck?

The inside of the 18-wheeler features four seats — two in the front and two in the back — with a monitor positioned near the driver’s seat and another monitor in the rear, typically for the observer.

“It could handle unprotected right turns, unprotected left turns, stop lights and stop signs,” said Robert Brown, vice president of business development at Bot Auto.

The truck was able to make turns on its own, drive in a straight line without drifting out of its lane, exit the highway, stop at stop signs, wait its turn during a four-way stop with the traffic lights blinking, yield for other vehicles and anticipate when another vehicle was trying to get over into its lane.

There was one instance when Nelson had to help the truck navigate a turn at an intersection. But during most of the trip, the vehicle maintained its course without human assistance, passing by places that included Katy High School, Buc-ees, Tiger Square and distribution companies without any incidents.

The cab shook at times while the truck was in motion. Bot Auto spokesperson Jeremy Desel explained that 18-wheelers tend to be slightly jerky compared to personal, smaller vehicles. For passengers in an autonomous truck, the ride may feel bumpy as the vehicle’s technology opts for the safest maneuver instead of the rider’s comfort.

Preparing the self-driving truck for the trip

Nelson said he has worked in the autonomous trucking industry for five years post-COVID-19 pandemic. He took a chance to enter into an industry that had a connection to his previous job as a trucker.

“Trucking was fun and different back then, whole different mindset, which is why I came over to autonomy,” he said.

Before getting on the road, Nelson checks his schedule, sets up the self-driving system, does a thorough pre-trip inspection on the truck, hooks up the trailer to the cab, and conducts another pre-trip inspection on the trailer.

Inside the cab, monitors show a virtual version of what the truck sees, including the lanes, other vehicles and objects. There are four shifts a day for testing the trucks, Brown said. The trucks have a large fuel tank that runs 1,400 miles.

“I think the key motivation is not about how to build a technology, it's how to create value … creating value for the customers, providing capacity, is what we're looking at,” Hou said.

Bot Auto hopes the trucks will create safer travel by removing humans from the driver’s seat for many tasks. The trucks don’t have to stop for breaks, and their systems won’t get distracted or fatigued.

Brown was no stranger to hearing the concerns about the potential impact on the workforce of companies that operate self-driving trucks.

“The human truck-driving job is not going away. It will be augmented by autonomous vehicles, but not eliminated by autonomous trucks,” Brown said. Human drivers will still be needed for complex tasks, he said.

“We can handle that long-haul running between Laredo to Atlanta, but we need those drivers on each end of that for the first and last mile to deliver those goods,” he added. A young truck driver entering the workforce today can still expect to retire as a truck driver in the future, he said.

How do the self-driving trucks work?

Bot Auto has six heavy-duty diesel 18-wheelers that use cameras, radars and lidar units. The mounted sensor array on the vehicle has eight lidar sensors and 15 high-definition cameras.

The trucks come from Houston Freightliner, which Bot Auto transitions the regular diesel trucks to autonomous vehicles.

The technology gives the trucks a 360-degree view and the ability to spot objects up to 500 meters ahead. They can also detect cars, motorcycles, bicycles and pedestrians.

“There’s redundant braking, redundant steering, redundant power supply, redundant (electronic control units), so everything is intentional that goes into the system. If one component fails, we have a backup of a backup,” Brown said.

Brown said the company is working to deploy the technology for wider use once it’s safe and secure. The goal is to make sure its trucks meet the needs of the freight business.

“What our customers care about is being on time, being safe and delivering products,” he said.