Amtrak adopts Delivery Partner model to deliver Baltimore tunnel project
https://www.railwaygazette.com/infrastructure/amtrak-adopts-delivery-partner-model-to-deliver-baltimore-tunnel-project/66257.article
The current Baltimore and Potomac Tunnel has the speed limit of 30 mph (48 km/h). It's the extreme curve for Acela Express.
So, alternative tunnel should be built soon.