Beginning Jan. 1, commuter buses in the cities of Shakopee and Prior Lake fall under the umbrella of the Minnesota Valley Transit Authority.

The two cities will join five others — Apple Valley, Burnsville, Eagan, Rosemount and Savage — that are already part of the MVTA. The merger was finalized in September and service will start Friday.

"We always had kind of contemplated in our thinking that perhaps one day we would merge completely with the MVTA," said Scott County Commissioner Jon Ulrich, an MVTA board member. Plans have picked up over the last few years, he said, particularly in light of a 2011 legislative auditor's report recommending consolidation.

The merger will bring the Shakopee circulator and the BlueXpress commuter service — a line run jointly by Shakopee and Prior Lake — into the MVTA.

Michael Leek, Shakopee's community development director, said the merger will increase efficiency and make it easier for the two cities to expand their transit service.

Plans are underway for a 2015 study, led by the MVTA, to examine possibilities for transit service in northern Scott County.

And starting Feb. 23, MVTA will begin offering an express bus route connecting Shakopee's Marschall Road Transit Station and downtown Minneapolis.

Many of these changes can be traced back several years to Scott County's Unified Transit Management Plan, Leek said.

"It really does go to the kinds of planning that we started doing in 2005," he said, "of putting together a more comprehensive, probably more south-of-the-river service."