How do semi$-$ and fully$-$autonomous self$-$driving cars differ?

Fully$-$autonomous vehicles are less energy efficient than semi$-$autonomous ones.

Semi$-$autonomous vehicles require no intervention from a human driver.

Semi$-$autonomous vehicles emit fewer pollutants into the atmosphere than fully$-$autonomous ones.

Fully$-$autonomous vehicles can manage the full range of on$-$road scenarios.