While the initiative carries an estimated daily expenditure of Rs 2 crore, the transport minister clarified that the exact liability can be assessed only after ticket data is available.
Operators warn that women, who constitute the backbone of their ridership, will abandon private buses entirely, leaving behind only students travelling on concession tickets.
Operationally, the district will lead the rollout with the highest fleet allocation of 687 ordinary buses, while Malappuram will operate the lowest at 98.
The free travel scheme for women would be formally inaugurated by Chief Minister V D Satheesan at the Thampanoor Bus Terminal in Thiruvananthapuram at 8.30 am on June 15.
Transport Minister C P John clarified that women travelling in ordinary buses will not be charged even if a passenger is willing to pay, citing practical and administrative difficulties.