Prior to the practical use of a new wayside signal aspect for high-speed trains in the Hokuhoku Line, its visibility and compatibility were tested about the signaling method which is of a double green aspect given before the appearance of a single green aspect for the proceed signal. Twenty four test runs were thoroughly performed with participation of twelve drivers, on the line of 30 km at the maximum speed of 160 km/h. Drivers succeeded in identifying without difficulty signals given by the new system for each of test runs.