The merger would create the United States’ first coast-to-coast rail network, spanning 50,000 miles and 43 states.

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.

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.