The author of a report that shows a growing income gap in Toronto says Transit City, or a plan like it, is key to reducing that disparity.

“That’s the way to go,’’ U of T professor and researcher David Hulchanski said of former mayor David Miller’s light rail plan, an initiative his successor, Mayor Rob Ford, announced he is cancelling in favour of building subways.

On Wednesday, Hulchanski released an update to his 2007 “Three Cities within Toronto” report. The study shows a continuing decrease of middle-income households while low-income families are on the rise. The problem is especially acute in the northeastern and northwestern parts of the city.

If current trends continue, 10 per cent of the city will be middle-income earners by 2025; 30 per cent will be upper-middle income; and 60 per cent of residents will be in the low to very low income bracket, Hulchanski predicts.

Expanding access to transit is among the key ingredients to slowing or reversing the “segregation’’ of the city by income, Hulchanski argues in his update.

“There’s a significant shortage of accessibility to transit. That’s why I’ve been a fan of the Transit City plan from the start. Linking many parts of (low-income) neighbourhoods and the northern part of the city not served by subways is just wonderful,’’ he said in an interview.

“It’s crucial for us to be one city,” he said, adding he hopes to meet with Ford or his staff to discuss the issue.

Ford and others have criticized Transit City, saying light rail lines create too much congestion for cars, in addition to protracted construction headaches for residents and business owners.

But many of Transit City’s light rail lines would have significant portions running underground, proponents argue.

Critics say the money isn’t there for subways, nor — at least as far as poorer communities are concerned — the time.

Hulchanski’s report notes that the lowest income areas of the city have only 19 subway stations close by.

Middle-income areas have access to 50 subway stops, while upper class neighbourhoods have 40 stations.

“Transit is a huge issue in Scarborough. We have a lot of visible minorities living in very vulnerable conditions. They’re looking for jobs, desperate for jobs and they have to (get) around, you know, with what?’’ Israt Ahmed, a community planner with Social Planning Toronto, told the news conference held Wednesday to announce Hulchanski’s findings.

“(Only) 19 subway stops. That speaks to the deprivation we have in our suburbs.’’