Tesla founder Elon Must believes there may eventually come a day when people are no longer allowed to drive vehicles because it's not safe.

Musk made the observation while speaking at a conference held by chipmaker Nvidia.

"In the distant future, I think people may outlaw driving cars because it's too dangerous," Musk said. "You can't have a person driving a two-ton death machine."

Nvidia supplies Tesla with processors for its all-electric vehicles, including its instrument cluster and large 17-in. infotainment center.

Later on Tuesday, Musk took to Twitter to clarify his position, saying, "when self-driving cars become safer than human-driven cars, the public may outlaw the latter. Hopefully not.

"To be clear, Tesla is strongly in favor of people being allowed to drive their cars and always will be. Hopefully, that is obvious," Musk wrote.

Thilo Koslowski, a vice president and distinguished analyst at Gartner for automotive advisory services, said the idea of laws requiring drivers to use autonomous functions in cars has been considered now for years and it makes sense.

A study by the non-profit Eno Center for Transportation revealed that if 90% of cars were self-driving, more than 21,000 lives a year would be saved and $450 billion in related costs would be eliminated.

Koslowski envisions a time in the not-so-distant future when drivers may come upon roadside signs telling them to hit the auto-drive button in cars because a certain stretch of road is particularly dangerous. Or, drivers may get incentives from insurance companies offering lower premiums to those who take advantage of autonomous functions.

"I definitely forsee a future like this," Kowslowski said. "Driving manually doesn't make a whole lot of sense. People used to wash clothes by hand. But if you did it today, people would think you're crazy."

Like tax incentives the federal government offers consumers who buy electric cars, Kowlowski said autonomous vehicles may also carry monetary rewards. Today, Koslowski said, automobile accident costs amount to about 2% of the gross domestic product; eliminating that expense and increasing efficiency by adding more time to work or surf the Internet during a commute to the office is too obvious a benefit to ignore.

Tesla is increasing the automated features in its vehicles, such as the use of cameras and sensors to enable adaptive cruise control. It is also working on a fully automated vehicle.

Many other major vehicle makers, such as GM, Mercedes, Audi, Nissan, Ford and others are revealing prototypes of fully autonomous vehicles. Google is also planning one between now and 2020. Koslowski said consumers should begin seeing self-driving vehicles in showrooms in the next two to three years. They'll be ubiquitous in 10 to 15 years, he said, though the government could accelerate that pace with purchase incentives.

"I almost view it as a solved problem," Musk said. "We know exactly what to do, and we'll solve it in a few years."