In NYC, because of the legacy taxi medallion system which artificially limited the number of medallions to 13,000 (resulting in a medallion market value of $1.2 million now down to $700,000 after Uber/Lyft), taxi fares are still about twice that of many US cities. The artificial limit of medallions created artificial scarcity which resulted in "economic rents" thus ultimately requiring passengers to pay much higher fares that then went to the medallion owners.
One example would be to lower gas usage by using electric vehicles or hybrid cars (NYC Yellow Taxis are converting to hybrids) which not only lowers fuel costs but lower air pollution. They could make a financial deal with the city or state showing the lower health care costs from lower air pollution and have the cars financed.