Municipal-bond investors are scouring for pockets of the $3.9 trillion market that are a haven from the coronavirus and its recession. Turns out toll roads may be a safe bet.

Governors in at least 11 states, including Michigan, Ohio and Connecticut, are pushing for new taxes, bond sales and tolls to raise money for long-needed work on roads, bridges and transit systems after President Donald Trump failed to enact a major infrastructure plan.