Driverless vehicles could threaten the jobs of millions of Americans who drive trucks and taxis. Some experts believe driverless trucks will be deployed throughout the United States soon. Others believe it will not happen for years.

In Australia and other countries, driverless trucks move large loads of dirt and ore in mines. The trucks can operate in the mines because there are few other vehicles there. But it will be more difficult for vehicles to operate on roads where there are many other vehicles.

Ted Scott is the head of engineering at the American Trucking Association. He says it will be years before rules are written, testing is completed and other drivers accept driverless vehicles.

The carmaker Volvo and the ride-sharing company Uber have announced a plan to test self-driving cars in the eastern city of Pittsburgh, Pennsylvania.

The Ford Motor Company recently announced it would work with a Chinese company to research self-driving vehicle technology.

Carmaker Audi and other companies are testing robot drivers in more complex environments. These include mountain roads in the United States and in large American cities.

Chan Leiu is a former official at the National Highway Traffic Safety Administration. He says these tests may help speed up the deployment of driverless vehicles.

Leiu says self-driving vehicles may help save lives. He says 94 percent of vehicle crashes are caused by human mistakes. These include driving while tired, writing on a digital device or after drinking too much alcohol.

Tim Carone is a professor at Notre Dame University. He says tens of thousands of lives could be saved if self-driving vehicles are deployed.

Rogelio Rada has been driving a truck for 16 years. He believes it will be a long time before robots take his job.

Barry Waters is also a truck driver. He believes robots will not be driving trucks for 20 or 30 years.

The Bureau of Labor Statistics says more than 1.7 million people worked in the trucking industry in 2014.

Many people are concerned about the effect of driverless cars on employment because manufacturing in the United States has been decreasing for years. The car manufacturing industry is no exception. American carmakers sold a record number of vehicles in 2015, but had far fewer workers than ever.

Carmakers now use robots to weld, paint and perform other tasks, often better than humans.

That is bad news for millions of workers like Holly Stover. She worked in steel mills for many years. “Well I hope to end up working a good, a decent job, making a decent living.”

Stover is working with an employment counselor to explore new kinds of work. She is also considering going back to school to learn new skills.

Anthony Carnavale is a workforce expert at Georgetown University. He says an increase in industrial robots means fewer humans will have high-paying manufacturing jobs.

“Probably 75 percent of the job loss is technology-based, which is to say robots -- machines in general -- are substituting for people.”

Chris Lu is the Deputy Secretary at the United States Department of Labor. He says the changing economy is creating new opportunities for workers if they have the skills.

Some employers in the United States complain that they cannot find enough workers who have the ability to operate advanced machines or program computers.

“We’ve also in this country had a remarkable transition to a service economy and really wonderful high-paying jobs in IT, for instance. Those are industries that didn’t exist 20 or 30 years ago.”

Greg Pitoniak is the head of the Southeast Michigan Community Alliance. He says his organization closely records the skills employers need and helps displaced workers meet those demands.

“Many job seekers look at it as ‘I can’t afford to go to school for a couple of years and not have an income,’” he says. He explains that employers are seeking workers they can train for high-paying jobs like electrician, plumber, carpenter, millwright and pipefitter.

Pitoniak says the American education system does not do enough to prepare some students for technical jobs.