The Silver Spring Transit Center is now expected to be open in late summer 2013, a full three years after initially planned, a Montgomery County official told lawmakers Thursday.

When it is completed, the $110 million concrete structure is expected to be a three-story hub for Metro, Montgomery County Ride On and Maryland Transit Administration commuter buses; taxis; Kiss and Ride; and Metro, MARC and, eventually, Purple Line trains. But the unfinished facility has been a massive construction zone in the middle of downtown Silver Spring since the fall of 2008.

The construction delays have generated complaints from residents about rerouted buses and worsened traffic.

"There is real confusion among bus riders of where to catch their bus, where they'll be dropped off and for people who walk to the Metro -- a lot of them have been detoured because of the construction site," said Evan Glass, chairman of the Silver Spring Citizens Advisory Board. "It is a very confusing part of town because everything has been displaced."

Though the project has been plagued by delays almost since it began, construction was almost finished about a year ago when the county discovered that the concrete on the top two levels was cracking and flaking, and that, as a result, some of the reinforcement steel was left exposed to the elements.

"A certain amount of cracking is understood to take place, is acceptable. The extent of the cracking and the nature of the cracking in this particular structure is of particular concern," David Dise, Montgomery County's Department of General Services director, explained Thursday. "Some of the cracks appear to go ... all the way through the deck to the bottom. We've observed moisture penetrating and dripping from underneath."

The county and Foulger-Pratt, the project's general contractor, plan to cover the cracks with a top coat, but they won't be able to do that until the weather gets warm again in the spring, Dise said. "At this point, we're looking for a late summer opening of the facility." A representative of Foulger-Pratt was not available for comment Thursday.