In the United States, the federal government will subsidize capital investments for mass transit systems (a/k/a buses, in most cities, also railway/busway in some), but not operating costs (drivers & mechanics). Labor costs are, in fact, one of the major costs of location transportation authorities.

When I lived in San Diego, the bus line by my house ran at half the frequency using buses twice as large on weekends, which I can see no explanation for other than saving money on labor by making transit service much less useful.