Amtrak and the Maryland Department of Transport (MDOT) have commenced the Baltimore and Potomac (B&P) Tunnel replacement project in the US after a prolonged delay.

This ageing tunnel is said to be the cause of constant slowdowns in West Baltimore.

The MDOT and Amtrak will execute the $4bn project in a phased manner. Under the preliminary implementation, two new high-capacity tunnel tubes will be built for electrified passenger trains.

The construction of two additional tunnel tubes, which are expected to be designed for freight trains in the future, has been postponed.

This project will lead to the eradication of diesel train emissions at a ventilation centre on North Avenue in West Baltimore.

In a statement, Amtrak said: “The changes will also save two years during construction and more than $1bn.”

The new tunnel will be named after the late Maryland-born and abolitionist leader Frederick Douglass and accommodate all MARC Penn Line and Amtrak trains.

The MDOT will also electrify its MARC commuter trains to support the new plan.

US Department of Transportation Deputy Secretary Polly Trottenberg said. “This project will modernise a critical part of the Northeast Corridor making the train work better for the nine million passengers that depend on it each year.”

Through a varied investment, the replacement programme is expected to transform a 6.4km segment of Baltimore’s Northeast Corridor.

Apart from the new tunnel, the project will cover the overhaul of bridges, track, and rail systems, and a new ADA-accessible West Baltimore MARC Station.

Amtrak is currently gearing up for construction work, developing final design, and initiating property acquisitions.

The primary construction activities on the tunnel’s southern approach are anticipated to commence in the next one to two years.

In April, Amtrak requested a further $5.4bn for the upcoming budget year starting 1 October 2021 from the US Congress to cover the negative impact of the Covid-19 pandemic.