Following the 1930s, NY 40 began to be reduced in size. In the early 1940s, NY 22 was realigned between Truthville and Whitehall to serve Comstock by way of NY 40 and US 4. As a result, NY 40 was truncated south to its junction with NY 149 in Hartford. The portion of NY 40's routing between Hartford and West Granville was a sub-par road at the time (deemed as a second and third-class highway by map cartographer General Drafting), which led the state to place the end of the route in Hartford instead. In the late 1950s, NY 40 was cut back on its southern end to begin at what had been the northern terminus of its overlap with US 4 in North Greenbush.