Self-driving cars someday will be commonplace in this country, a panel of experts affirmed at a robotics conference in downtown St. Paul on Tuesday.

But it won’t happen in the next few years — and could take decades — given the many roadblocks in the way of such technology flourishing on U.S. highways, the panelists added.

After all, safety belts once were considered exotic and faced fierce opposition from auto makers, the public and others, said Chris Lund, product manager for land and sea navigation products at Honeywell.

Seat belts were patented in the late 1800s but weren’t regarded as essential car gear until a century or so later, Lund noted.

Lund and fellow panelists were among the tech attractions at Robotics Alley Conference & Expo, an annual robotics-industry gathering being held at St. Paul RiverCentre through Wednesday. The event is sponsored by Edina-based ReconRobotics, a designer of compact robots for military and law enforcement use.

The conference is mostly aimed at showcasing what its promoters believe is a growing Midwestern industrial cluster of big and small robotics companies and suppliers.

The break-out session on auto-driving vehicles was a highlight.

Autonomous cars that navigate on their own aren’t science fiction.

Google, for instance, has been experimenting with such vehicles for years, and has had a fleet of the self-driving autos on U.S. roads nonstop during that time.

Google has kickstarted a national and worldwide conversation — including Tuesday’s tech panel — about self-driving vehicles, said Scott Paxton, a partner at Bowman and Brooke, a Twin Cities law firm that specializes in motor-vehicle casework.

“Google has moved this forward,” Paxton said.

Even so, autonomous vehicles face fearsome obstacles in this country — which is why this technology could first become commonplace in other countries. Japan and the European Union are among areas where autonomous-car experimentation is taking place, Paxton noted.

“I put my money on China,” added Frank Douma, a research fellow at the Hubert H. Humphrey School of Public Affairs at the University of Minnesota.

For self-driving cars to take off in the United States, according to the panel, the following would need to happen:

— Relevant traffic laws assume a human is in control if a vehicle, and “laws and regulations need to start recognizing the technology,” Douma said.

— Technology must be refined so it’s clear when it is appropriate for a car to be in control, and when a human inside the vehicle would have to intervene, said Leili Fatehi, adjunct professor and research fellow at the Humphrey School of Public Affairs and the University of Minnesota’s Law School.

— The cost of this technology, now far beyond the reach of average consumers, needs to come down, Paxton said.

— Liability laws need to be refined so that lawsuits related to autonomous-car accidents don’t kill the technology, Paxton added.

— The problem of driver inattention needs to be addressed somehow.

People in self-driven vehicles could become complacent to the point of being incapable of acting in time when their intervention is required.

Yet the long-term benefits of such technology seem clear to some.

Paxton sees “safer, faster, less congested roads with cars that can drive closer to each other without having to jam on the brakes.”

Fatehi envisions a golden age of ride sharing with self-driven vehicles in carpool lanes.

Douma sees freedom for those too young, too old or too disabled to drive.

And Lund fantasizes about having a “virtual chauffeur” that would allow passengers to read and do work during their commute.