Prime Minister Stephen Harper, standing at the east gates of Banff National Park, announces the further twinning of the Trans-Canada Highway. (Jeff McIntosh/Canadian Press)

The federal government is spending $100 million to widen a dangerous two-lane stretch of the Trans-Canada Highway through the Rocky Mountains.

On Tuesday, Prime Minister Stephen Harper announced the three-year project, which will twin a 14-kilometre stretch between Castle Junction and Lake Louise.

“Every year, thousands of Canadians and visitors from around the world visit Banff and travel this highway, whether they are tourists, businesspeople, or just visiting family,” the PM said. “Residents and visitors alike know this to be one of the most beautiful drives in the world. They also deserve for it to be one of the safest.”

Harper said the highway has an accident rate 17 times higher than the Alberta average.

A report by Parks Canada had previously recommended twinning 33 kilometres of the highway from the Castle Junction to the B.C. border.

The first phase of expanding 10 kilometres east of Lake Louise, which began in 2005, is expected to be finished late this year. When completed, the entire roadway between Lake Louise and Calgary will be twinned.

Harper credited Myron Thompson, the Alberta Conservative Member of Parliament for Wild Rose, for pushing the project through.

"Myron began lobbying for this in 1993 and for the first 13 years, he had a government that didn't listen," said Harper, standing at the gates of Banff National Park. "Since we took office, we've been getting on the serious large-scale infrastructure development across the country."

Twelve people have died on the highway around Lake Louise in the past six years, including three in a semi-trailer pileup in January.