Certainly, government fund can improve public transport services. By allocating investment to advanced vehicles, maintain infrastructure, and introduce intelligent technology, they can ensure that public transport meets the demands of citizens. For example, Singapore has already using tax revenues to establish effective public transportation networks to attract more users and reduces the reliance of private cars.
It also plays a pivotal role in making bus and metro services more affordable. Many individuals rely on public transportation for their commutes, including low income families and students. By providing free services, government can guarantee that is accessible for everyone. Thus they can reduce inequality between poor and rich. For instance, cities like guangzhou and shanghai, there has subsidized policy to elderly people and disabilities when they using public transportation.
However, that does not justify a free access, for it can lead to overcrowding. Demand will definitely explode with the number of passengers increases. Government have to distribute more vehicles to meet the needs of them, because the carrying capacity is limited for those free services. Moreover, it may cause overuse of public transportation when without fare limitation. Some of residents would see taking free buses within cities as a way to kill time because of the convenience and comfort provided by buses.