@madness832 Fares are often a tiny amount of a transit system's cost. With the MBTA, fare revenue is around 15%, but some of that is lost to the cost of collecting fares (the cost of the machines, electricity to run them, credit card fees, the cost of producing fare cards, the cost of maintaining all those systems working, the cost of staff for technical support, etc).
When fare recovery is such a tiny fraction of revenue and you want to encourage additional ridership (which will lower pollution, congestion, parking demands, road maintenance, etc), fares might not be the best policy.
And fares have hidden costs. If people drive more because of fares, that means more road maintenance costs. If there's more traffic from more drivers, that's people losing time from their lives. Collecting fares can slow boarding on busses requiring more fuel idling and more busses/drivers to service the routes.
In this case, they were getting $1.5M in fares, but got $2M in benefits from eliminating fares so it was a net win.