The railroad was noted for the fast speed of its trains by 1848, when a Hartford and New Haven passenger train made the trip from Springfield to Hartford at an average speed of . The Hartford Weekly Times asserted that "This is the quickest trip ever made in this country with a heavy train over any railroad, and the road is now regularly run with greater speed than any other railroad in the United States, and with double the average velocity of railroads out of New England." The railroad's largely straight alignment, which followed natural topography and the Connecticut River, made this possible.
