symbol p indicates the central plane of the plate assembly 3 fig7 is a bottom view of the stationary board wherein the column support 4 is partially cut out the column support 4 is also formed in a hollow structure of a plastic martial it is not essential to provide transparency in the column support in the medial strip 2 having a plural number of the above stationary boards 1 set up therealong at given intervals for example of 5 to 7 m as shown in fig1 the light from a vehicle in the opposite lane at night is incident on the surface of the plate assembly 3 of the stationary board 1 then the incident light is scattered by the irregularities formed in the inner surface of the central region 7 and the six sided pyramid shaped protrusions 18 formed in the inner surface of the peripheral region 8 in each of the plate members 5 6 this scattering effect prevents the light of the oncoming vehicle from dazzling or negatively influencing a driver or rider in a lane facing the light in addition the coat layer 17 of a luminous material formed on the inner surface of the marginal region 9 in each of the plate members stores energy of exciting lights from outside to allow the marginal portion of the stationary board to emit light in dark condition so as to help drivers or riders identify the position of the medial strip preferably the plate assembly 3 of the stationary board 1 is designed to have a height of 600 to 700 mm and a width of 400 to 450 mm and is set up in the medial strip through the column support 4 at a total height of 1400 to 1500 mm referring.