By John Ostapkovich

PHILADELPHIA (CBS) — Amtrak is out with a new capital investment plan for the Northeast Corridor — a plan which extends far beyond the money currently in the transportation agency’s pipeline.

This plan merges years of work on improving existing service with a bold vision for the next four decades that could include an airport stop and a tunnel in Philadelphia.

Amtrak spokesman Steven Kulm says this “stairstep” plan includes, on the lower end, more Acela cars and trainsets, and on the upper end new track capable of hosting high-speed “bullet” trains.

The vast majority of this $100-billion-plus dream is unfunded, but Kulm says you have to have a blueprint.

“We want to have a plan in place that, when money becomes available, we can do things that will increase speeds, reduce trip times, improve capacity, and basically improve reliability,” he tells KYW Newsradio.

One part that is already funded is track improvements between Trenton and New Brunswick, to allow speeds of up to 160 mph.