Real estate investors have spent more than $1 billion acquiring properties near the QLine rail route, gobbling up buildings near future rail stations and in Highland Park in hopes the project will be extended northward.

The activity — including more than $350 million worth of property acquisitions by QLine backer and Quicken Loans Inc. and Rock Ventures LLC founder and Chairman Dan Gilbert — illustrates the economic impact of several developments along the Woodward Avenue corridor. Those include the rail line, a possible bus rapid transit system, a new Amtrak center and the Detroit Red Wings arena.

All told, the economic impact of transit-oriented development is expected to top $3.5 billion within a decade, M-1 Rail officials say, and include a mix of 10,000 new residential units, offices and commercial projects clustered near Woodward.

The investment also shows the symbiotic relationship behind Gilbert’s backing of the QLine, which is expected to send property values soaring, including pieces of the billionaire’s downtown real estate portfolio. Quicken is paying $5 million over 10 years for the naming rights to the $140 million rail project and is the largest single corporate contributor at $10 million.

“It’s brilliant for him to help fund the line. It shores up his real estate investments. He’s not doing it for charity,” said Robert Gibbs, managing principal of Birmingham-based Gibbs Planning Group Inc. “A lot of developers in cities nationwide built these transportation lines really as a real estate development tool.”

Gilbert always viewed the rail project as the first step toward establishing a regional transit system while generating economic development, said Matt Cullen, president and CEO of Rock Ventures.

Gilbert never would have started investing nearly $2.2 billion in acquiring, renovating and developing more than 85 properties in downtown without transit, Cullen said.

“Dan always said, ‘I’m only coming (downtown) if there’s transit,’” Cullen said. “We hope the QLine is an economic development driver, but that it also will be the catalyst for regional transit.”

Rail projects nationwide have sent real estate values soaring.

A recent study in Denver showed office rents and property values near light-rail stations were 300 to 400 percent higher.

Land near QLine stations is drawing investors in Detroit.

Real estate transaction data from Southfield-based CoStar Group Inc. shows several properties along Woodward changing hands in recent months, particularly near three corners of the Woodward and Grand Boulevard intersection, the northernmost stop along the QLine.

Since 2011, approximately $1.3 billion in new real estate developments have broken ground, debuted or been announced, Cullen said. About half of that figure, $627 million, is due to the new Red Wings arena.

The $1.3 billion figure is in line with studies by the American Public Transportation Association, which shows that every $1 invested in public transportation generates about up to $8 in economic returns.

The QLine has inspired economic activity along the Woodward corridor since the rail project was unveiled in 2011, Cullen said.

“I know it did. No doubt,” Cullen said. “Suddenly, people are buying and fixing up buildings.”

The CoStar data does not include sales prices for every property, so the total amount of sales is likely much higher than $1 billion.