The concurrency was reduced slightly in the mid-1940s, however, as NY 24 was rerouted to follow the Crosstown Connecting Highway (now the right-of-way of I-278) and Midtown Highway (I-495) to the Queens–Midtown Tunnel. It then continued through the tunnel to end at NY 1A in Manhattan. The Crosstown Connection Highway and the Midtown Highway were upgraded into the first portions of the Brooklyn–Queens Expressway (BQE) and the Queens Midtown Expressway, respectively, in the early 1950s.
In the mid-1940s, the concurrency was slightly diminished as NY 24 was rerouted to follow the Crosstown Connecting Highway (now I-278) and Midtown Highway (I-495) to the Queens–Midtown Tunnel. It then proceeded through the tunnel to end at NY 1A in Manhattan. The Crosstown Connecting Highway and Midtown Highway were later incorporated into the Brooklyn–Queens Expressway (BQE) and Queens Midtown Expressway, respectively, beginning in the early 1950s.