Four roads in Butler County will receive an extra $11.6 million worth of improvements this year because of the state’s new transportation law.

Gov. Tom Corbett announced on Thursday that $2.1 billion in statewide highway and bridge projects will begin in 2014, according to the state Department of Transportation.

That figure is $600 million more than what would have been available without Act 89, which raised a gas tax and a number of vehicle and driving licensing fees.

The state roads in the county were added to the state’s project list are:

A 3.5-mille stretch of Route 228 from Saxonburg Boulevard to Route 356 in Clinton and Buffalo townships will receive patching, drainage, and resurfacing work.

The project will be done by the Derry Construction Co. of Latrobe for about $3 million. Work is expected to begin this spring and be done by the end of August.

A 3.6-mile stretch of Route 422 from Route 528 to the Mt. Chestnut Bridge in Franklin Township is expected to be finished by the end of August.

The estimated $2.7 million project will be done by Glenn O. Hawbaker, Inc.

Route 356 from Green Manor Drive to Route 8 in Summit and Butler townships also will be repaved. Repairs on the 3.9 mile stretch of road is expected to cost about $1.8 million.

An estimated $4.1 million will go to repaving 3.4 miles of Yellow Creek Road in Lancaster Township.