Construction to equip all of the Hiawatha light-rail stations to handle longer trains -- as well as build another station in Bloomington -- is ahead of schedule and should be finished by the end of the year, Hennepin County Board members learned Tuesday.

That means that trains with three articulated cars, rather than just two, will be on the tracks and pulling into the new ballpark station by the time the Twins inaugurate Target Field in April, Metro Transit engineer MarySue Abel told the board.

Why the need for longer trains? Because the five-year-old light-rail line, which connects downtown Minneapolis with the airport and the Mall of America, has become a hugely popular transit option.

Last year the line topped 10 million rides, 12 percent more than in 2007. An average of 37,000 commuters rode the trains daily during weekday rush hours.

"The success of the line has really proven that we need to accommodate more ridership," Abel said.

So Metro Transit, using funding from federal and local sources, is lengthening the platforms at nine stations, adapting two downtown stations for the longer trains and replacing scores of bumpy yellow warning strips dislodged by the annual freeze-thaw cycle.

Signals at track crossings are being upgraded to permit trains to run more efficiently in reverse when needed.

The agency also is building a new station that had been planned years ago but was dropped because of cost overruns. The new stop, at American Boulevard and 34th Avenue, will be the fourth station on the line in Bloomington.

The total cost of the expansion projects is about $13.5 million. Extending the platforms costs $9.3 million, while the new American Boulevard station is $2.2 million, Abel said.

Most of that money comes from federal coffers, with additional funding from the Metropolitan Council, Hennepin County and Bloomington.

Questions from board members centered on the artwork for the expanded stations. Abel said that it will mostly extend and duplicate what's already in place, but some commissioners were disappointed to learn that the original artists were from outside the area.

With all the local art communities, Mike Opat said, it seems "ridiculous" to look outside the Twin Cities for people to decorate the stations. Mark Stenglein suggested that the county seek local artists for the proposed southwest light-rail line, and Peter McLaughlin said that most of the artists selected for the Central Corridor line are local.

The reason why artists for the LRT lines aren't all Minnesotans is that the projects receive federal funding, said Laura Baenen, a spokeswoman for the Central Corridor line. Such projects must meet federal guidelines that open the hiring process to people outside the state, she said.

When the Hiawatha line opened in 2004, seven of the then-17 stations were built long enough to handle three-car trains. With all stations now being readied to accommodate them, new trains will be purchased for use by 2012, Abel said.

Work on the stations began in April. Light-rail service has been interrupted periodically since then because of construction, and there may be one more such shutdown before the job is finished, she said.

The station at Cedar-Riverside will be closed over the weekend for platform work.

Kevin Duchschere • 612-673-4455