The network carried about 7.7 million passengers in the programme's first four weeks, with weekly ridership up 33-45 per cent, including around 45 per cent in the fourth week.
Authorities estimate the network carried more than 8.4 million passengers in July, an increase of about 39 per cent year-on-year.
Officials said the growth reversed the usual seasonal decline during the summer school holidays, when student travel typically falls.
Ridership on urban routes rose by about 38 per cent, while unsubsidised and interprovincial routes recorded growth of 64 per cent. Some routes serving the former Binh Duong area saw passenger numbers more than double.
The city's on-time rate reached 97 per cent, exceeding its 95 per cent target, while electronic ticket validation rose to more than 60 per cent from around 9 per cent before the fare-free policy.
Authorities said the policy has helped reduce travel costs, encouraged more people to switch from private vehicles to public transport and laid the groundwork for a more integrated transport network.