Self-driving cars could be on the road in large numbers sooner than anyone expected — possibly by 2021 — even if public support for autonomous vehicles appears to be dropping.

Despite his lame-duck status, Connecticut Gov. Dannel P. Malloy is ordering a $10 million study on placing electronic tolls on the state’s highways and finding ways to fund needed transportation improvements.

Connecticut is obtaining $7.5 million from the national Volkswagen settlement over emissions cheating and will use the funds to help replace aging diesel trucks and other equipment.