All of the following methods of signal supports are included except:

The correct choice is that arched supports are not typically classified as a standard method of traffic signal supports. In traffic signal design, common support methods include pedestal supports, which provide a stable base for signals often in pedestrian areas; monotube supports, which feature a single, often tapered pole allowing for a cleaner aesthetic and reduced wind load; and truss supports, which are typically used for overhead signals over wide intersections or roadways, offering additional structural support.

Arched supports, while they might exist in some forms, are not considered a standard or widely recognized method for mounting traffic signal heads in typical configurations. Therefore, arched supports do not fall within the established categories of traffic signal supports that technicians would commonly encounter or be trained on. Understanding the various methods of signal supports is essential for ensuring that traffic signals are installed safely and effectively in different environments.