No. Both planks are needed for the correct system. The lower panel is needed for those that are partially sighted and use a cane to detect obstacles.
Their cane will not find barrier and they may then walk into to the top rail and fall into the hazard, for this reason, the lower rail is known as the Tapping Rail.
The tapping rail can be a plain board, but this board should not be put into the top position as the contrasting red and white panels make the system more visible.