Pittsburgh tech companies raised just over $3 billion in funding last year, led by landmark investments in autonomous vehicle startups like Aurora and Stack AV.

The pivot from self-driving cars to self-driving trucks is the latest sign of how difficult it is to fully take our hands off the wheel, industry experts and researchers say.

The founders of the former self-driving unit of Ford Motor Co. and Volkswagen AG are launching a new autonomous trucking startup, Stack AV,  with backing said to be more than $1 billion.