YOKOHAMA, Japan — Nissan has long stressed the necessity of keeping your hands on the wheel when using its ProPilot Assist semi-autonomous driving technology in the United States.

But it is now touting truly hands-free driving as early as this fall in its Japan home market. That's when the second-generation ProPilot system arrives, fulfilling Nissan Motor Co.'s promise to launch a self-driving system with automatic navigation for highways by the end of the decade.

Unveiled last week as ProPilot 2.0, the upgrade makes several advances over the current system, which has been sold in 350,000 vehicles worldwide since hitting the market in 2016.

Chief among the advances will be delivering pure hands-off highway driving from on-ramp to off-ramp. The system will switch lanes, pass other cars and help with lane exiting.

The current system doesn't allow lane changing or take orders from the navigation system to drive itself to a chosen destination. And in the U.S., a circumspect Nissan tacks the word "Assist" onto the ProPilot name so as not to engender a false sense of security in its limited abilities.

The new technology will keep Nissan at the head of the pack in the emerging field of autonomous driving, a key focus of Nissan's brand-building strategy, said Tetsuya Iijima, general manager of the automaker's autonomous driving development department.

"All of the functions are the world's highest level," Iijima said last week during a briefing here at Nissan's global headquarters to unveil the new system. "It is going to be very difficult for others to top this and overtake us. We have integrated the most advanced-level technologies."

ProPilot 2.0 integrates a collection of seven cameras, five radar sensors and 12 sonar sensors. It tops the package off with a 3D high-definition navigation system. However, it does not use lidar, the laser-based sensor technology that is now the rage in the autonomous driving world. Iijima said Nissan's amalgam of sensors and mapping is just as good.

But there are still a few caveats;