Together, the two would create the first transcontinental freight rail in the United States and the largest freight rail network in the country

The Surface Transportation Board said on Wednesday that Union Pacific and Norfolk Southern have formally filed a notice of intent to combine, triggering the U.S. regulatory review process for a proposed $85 billion merger between the two major railroads.

Big mergers sometimes lead to big layoffs. Might that happen in the Harrisburg area — home to a giant Norfolk Southern hub — if Union Pacific completes its buyout of Norfolk Southern? Probably not, according to one industry expert.