Halifax unveiled plans for the 13-year demolition and redevelopment of the Cogswell Interchange on Friday.

The design stage alone will take almost two years and the demolition could last for four years. Redevelopment could take up to 13 years.

Ekistics Planning & Design’s blueprint suggests replacing the “concrete albatross” with two roundabouts.

The demolition would come in three stages:

Build a Northern gateway roundabout. Turn Cogswell Street into a four-lane route between North Park and Water streets, allowing part of Rainnie Drive to close and be turned into a green space. Build a Barrington Street roundabout. This would cause the biggest traffic disruption and likely require night work.

Cogswell Street could get a view plane protection to the harbour, the report suggests.

A transit hub would go at the top of Granville Mall, where a number of parks would be added. A separate bike path would be built between the Macdonald Bridge and Historic Properties.

It's a relic of a different time, an outdated idea of cities. - Mayor Mike Savage

The sewage treatment plant could be used to create energy for the district.

The new neighbourhood would be mainly residential, with shorter buildings near the Historic Properties and taller buildings (14 to 20 storeys) placed in the centre.

The plans oppose a mega-project like a stadium, as it would mess up the street grid. Smaller public buildings, such as an art centre, could be a good fit, recommends the report.

Halifax's executive committee, which comprises the mayor and city managers, will discuss the plans Monday.

The interchange was built in the 1960s to connect to Harbour Drive, a waterfront highway that was never built. Halifax has been considering getting rid of it since the 1990s, the report says.

“It’s a relic of a different time, an outdated idea of cities,” Mayor Mike Savage says in the report.

The report's authors put a positive spin on the interchange.

“On the other hand, the sprawling, over-designed auto-centric monolith has become a valuable land-bank for the city; an unintended gift from one generation to the next, of 16 acres of prime downtown land,” the report says.

“It is this generation’s duty to reprioritize a program for the land and to reimagine a place where people take the centre stage over the automobile.”

The report does not estimate the cost of the demolition, nor the potential revenues from redevelopment. The consultants do say the sale of land for redevelopment will likely bring in a bit more than the cost of demolition and street reconstruction.