The proposed expansion of the Toronto Transit Commission's Spadina line to Vaughan will be a major catalyst to population growth, driving up resale values by as much as 20 per cent in neighbourhoods along the new corridor, says a new study.

"After so many years, it's exciting to see so much attention being given by the federal and provincial governments to building infrastructure and transportation in the GTA," analyst and study author Don Campbell said in an interview.

In the 27-page report released yesterday, the six-station expansion of the TTC's Spadina line is the top choice to benefit from future transportation changes in the Greater Toronto Area.

"Accessibility is a critical determinant of residential land values and the improved access between urban centres and residential neighbourhoods greatly improves the value of homes," says the study, The GTA Transportation Effect, which looks at how transportation changes affect housing values.

The TTC plans to build new stops, starting with an extension to York University and ending at Vaughan Corporate Centre by 2014.

Campbell estimates the biggest impact would occur within an 800-metre radius of planned stations.