WASHINGTON (AP) – President Joe Biden is heading to Baltimore to visit an aging rail tunnel that’s slated to be replaced with help from bipartisan infrastructure legislation that he signed in 2021. The Baltimore and Potomac Tunnel project is estimated to cost $4 billion and take a decade to finish. It would eliminate a troublesome bottleneck that delays commuters and travelers up and down the East Coast. It’s the first of two rail-related stops this week for Biden, who was a regular Amtrak commuter during his years in the Senate. He’s visiting New York on Tuesday as another new tunnel is planned, this one under the Hudson River.