Weiner Ventures this week filed formal plans with the BPDA for two towers - one 39 stories - of apartments and condos on air rights over the turnpike along Boylston Street across Dalton Street from the Hynes.

Both towers would sit atop a six- or seven-story "podium" housing two floors of retail space topped by a four-story garage.

The taller tower, which would house 160 condos, would rise up to 586 feet; the second tower, which would house 182 apartments, would be 23 stories including the podium space, or up to 301 feet high.

The project, which would also use small existing but vacant parcels, would include a 303-space garage and some retail space.

Weiner hopes to begin construction in early 2018, with residential occupancy by mid-2021.

1000 Boylston St. project notification form (47M PDF).

From the filing:

The Project will transform the Project Site from an undeveloped highway overpass into a hub of residential and retail activity, which will help knit together the fabric of the City. The Project will provide a new connection between the Back Bay neighborhood, the bustling Massachusetts Avenue corridor south of Boylston Street and the Fenway neighborhood. This connection will be strengthened by street-level retail and an improved streetscape that will provide significant urban design and social benefits, as well as stimulate economic growth.

Prudential building on left, other proposed building in middle, 1000 Boylston: