Construction began last week on a "vertical connection" from the Green Line light-rail Central Station in downtown St. Paul to the skyway system.
The cost of the $1.7 million connection is being paid for through a grant from the federal government, with the balance from a Metropolitan Council light-rail construction contingency fund.
"Central Station will be one of the busiest stations along the Green Line, so connecting it to the heart of downtown is critical," said Mayor Chris Coleman.
The elevator will access the skyway at Fifth and Cedar streets.
Accessibility advocates raised alarms when it appeared there would be no way for disabled riders to reach the skyway. Rick Cardenas, co-director of Advocating Change Today, said the elevator will make it easier for people with disabilities, seniors and others to get to such places as the Xcel Energy Center, home and work through the skyway.