The average worker in the Twin Cities can reach nearly 17,000 jobs within a half-hour when traveling by transit.

The metro area's ranking, 13th in the nation, declined 1.6 percent over the past year in annually updated research released this week from the Accessibility Observatory at the University of Minnesota.

The study provides a fascinating glimpse into how transit connects people to their jobs nationwide.

"Transit is only half of the picture," explained Andrew Owen, director of the Observatory. "The other half of the equation is where are the jobs and where are the workers."

Total employment in the metro area has remained steady at 1.7 million jobs.

"The [Twin Cities'] decline probably isn't entirely explained by change in job patterns or a change in transit, which hasn't changed that much," Owen said. "A large part of it is where people live. We saw growth throughout the region, a lot of it in suburban and exurban places, which are difficult to access by transit."

The dearth of transit in the metro's suburban employment centers has been well documented. For example, a patchwork system of private buses and shuttles ferries employees in downtown Minneapolis to suburban employers such as Amazon in Shakopee and Legendary Baking in Chaska.

Owen said that if all the job growth had occurred in downtown Minneapolis — which is well-served by both bus service and light-rail — "it would be hard not to see an increase" in the overall ranking.

The study found bigger cities, such as New York, San Francisco and Chicago, rank highest in the nation for transit systems that are easily accessible to jobs.

But metro areas such as Seattle and Denver, which are often seen as peers to Minneapolis-St. Paul, ranked higher than the Twin Cities.

Metropolitan Council Chairwoman Alene Tchourumoff said in a statement this week that the regional planning body needs additional funding to expand the Twin Cities' current transit system.

"Transit is just one part of a larger transportation system that is essential to the region's overall economy," Tchourumoff said. "Our peer regions have recognized that investing in transit makes good economic sense. Cincinnati and Seattle both saw double-digit increases in job accessibility by transit, while Milwaukee saw an increase of 6.5 percent."

Cincinnati added a streetcar in its downtown core and bought new buses, which Owen said explains why it saw the top increase in the number of jobs in the country. Seattle raised its local dedicated transit tax and invested in new buses, as well. "It's had a huge impact," he said, adding that even a small investment in transit can result in big returns.

Tchourumoff said that the study confirms what the Met Council already knew about the Twin Cities: "The region is growing and demand for transit is growing with it. By 2040, our region is expected to add more than 300,000 jobs."

Several new options may be added to the Twin Cities' transit mix by then.

Both the Southwest and Bottineau light-rail projects are expected to begin service in 2022 — the first LRT service to link employment centers in the southwestern and northern suburbs to both downtowns.

In addition, the Gold Line, the region's first bus-rapid transit line linking downtown St. Paul to the eastern suburbs along a dedicated lane, is in the works. And so is a proposed Riverview streetcar line connecting Union Depot in St. Paul to the Minneapolis-St. Paul International Airport and the Mall of America.

These bigger transit projects, which are expected to cost more than $5 billion to build, are dependent on federal matching funds, which are somewhat uncertain in Congress at this point.

Smaller bus projects, such as the Orange Line, connecting downtown Minneapolis to Burnsville, are also planned.

Each year, the Observatory ranks 49 of the 50 largest metro areas by population for connecting workers with jobs via transit. The research was sponsored by the Minnesota Department of Transportation and supported by the Federal Highway Administration and 11 other state transportation departments.