Which speed classification is defined as not exceeding 40mph for freight trains?

The classification defined as not exceeding 40 mph for freight trains aligns with "Limited Speed." This term is critical in railroad operations, particularly concerning the safe and efficient movement of freight. Limited Speed typically reflects a requirement to operate at lower speeds, enhancing safety in areas where track conditions, visibility, or other factors may necessitate slower operation.

In practical terms, this classification helps ensure that trains can navigate specific segments of track safely without risking derailment or accidents, particularly where there might be higher concentrations of work crews or other hazards. By maintaining freight trains at this specified maximum speed, rail operators can also manage the dynamics of heavier loads more effectively, minimizing wear on tracks and reducing the possibility of accidents.

While other speed classifications exist, they pertain to different maximum speeds or operational conditions that are not applicable when it comes to freight trains operating under the stipulations of Limited Speed.