Even though the Madras High Court had banned hoardings in public places, an AIADMK party official C. Jayagopal had put up the banner at the centre of the busy Pallavaram-Thoraipakkam Radial Road.
Subashree was returning home from office when the accident happened.
The banner had the images of Chief Minister K. Palaniswami, Deputy Chief Minister O. Panneerselvam, late Chief Minister J. Jayalalithaa and others for a family wedding.
Panneersevlam had attended that wedding.
Expressing his condolence for Subashree's death DMK President M.K.Stalin tweeted: "How many lives have to be sacrificed for such arrogance of power."
He said, an illegal hoarding had killed Subashree owing to government's carelessness, irresponsibility of the officials and the inability of the police.
Action has been initiated against the people who had installed the banner and have arrested the tanker driver for rash driving, the police said.
The Chennai Corporation has sealed the printing press that printed the banner.