SANTA CLARA, Calif. — Even as Google tests its small fleet of self-driving vehicles on California highways, legal scholars and government officials are warning that society has only begun wrestling with the changes that would be required in a system created a century ago to meet the challenge of horseless carriages.

What happens if a police officer wants to pull one of these vehicles over? When it stops at a four-way intersection, would it be too polite to take its turn ahead of aggressive human drivers (or equally polite robots)? What sort of insurance would it need?

These and other implications of what Google calls autonomous vehicles were debated by Silicon Valley technologists, legal scholars and government regulators last week at a daylong symposium sponsored by the Law Review and High Tech Law Institute at Santa Clara University.

As Google has demonstrated, computerized systems that replace human drivers are now largely workable and could greatly limit human error, which causes most of the 33,000 deaths and 1.2 million injuries that now occur each year on the nation’s roads.