U.S. Transportation Secretary Pete Buttigieg on Wednesday said federal policy on autonomous vehicles will undergo “meaningful” developments in the coming years, saying policy frameworks had not fully caught up with technological developments.

Speaking at the South by Southwest music, technology and film festival (SXSW), Buttigieg said regulation had to set boundaries for self-driving without stifling innovation in an industry that “is still largely in its infancy.”..

Buttigieg on Wednesday also said he wanted to improve the U.S. public transit system and encourage Americans to buy electric vehicles through government tax incentives to reduce emissions.

National U.S. transit use remains some 40% below pre-pandemic levels, according to data from mobility app Transit.