The picture shows the test train being repositioned (the jet propulsion does not lend itself to being reversed.) Find the accompanying discussion and an additional picture here. There are some notes on the speeds obtained here, and here is an impression of the test run. (For an April Fool story based on the jet test, read this.)
The New York Central used the occasion of its speed test to announce its intention to discontinue all passenger trains running more than 200 miles, including the famous Twentieth Century Limited, in favor of short-haul service in populated corridors. Amtrak's Empire Corridor along the Hudson and Mohawk rivers in New York is the only part of that project that came to fruition. You will search the rails of the New York Central in vain for frequent service between Chicago and Indianapolis, Chicago and Cleveland, Cleveland and Cincinnati, Buffalo and Cleveland, and other thickly settled areas.
And let us not praise American can-do spirit on the rails until one improves on these schedules.