A safety barrier post (5, 5') with a road sign retaining device on the safety barrier post (5, 5'), wherein the device has a receiving tube (1, 1') for receiving a shaft tube of the road sign with a securing element (4, 4') for locking and unlocking the receiving tube (1, 1') on the safety barrier post (5, 5'), wherein the securing element (4, 4') comprises a clamping element (4, 4') which is fixedly connected to the receiving tube, said clamping element - having a base body which is connected to the receiving tube, - having a first clamping jaw (12, 12') and a second clamping jaw (13, 13'), wherein the first clamping jaw (12, 12') and/or the second clamping jaw (13, 13') is/are arranged so as to be adjustable in a direction transverse to the longitudinal extension of the safety barrier post (5, 5'), - having an adjustment element for moving the clamping element (4, 4') into a securing position in which the first clamping jaw (12, 12') and the second clamping jaw (13, 13') exert a clamping force (F S) directed transversely to the longitudinal extension of the safety barrier post (5, 5') on the same, and for moving the clamping element (4, 4') into a non-securing position in which the first clamping jaw (12, 12') and the second clamping jaw (13, 13') do not exert a clamping force on the safety barrier post (5, 5'), characterized in that the adjustment element is formed as a threaded rod which is in threaded engagement with the first clamping jaw (12, 12') and/or the second clamping jaw (13, 13'), the adjustable first clamping jaw (12, 12') is movable relative to the base body of the clamping element (4, 4') along an adjustment path running perpendicular to a longitudinal extension of the safety barrier post, wherein front ends of the bar-shaped first clamping jaw (12, 12') are slidably mounted on a guide surface of the base body running in the direction of the adjustment path, and the first clamping jaw (12, 12') has a through-bore with an internal thread for the threaded rod, the second clamping jaw (13, 13') is formed so as to be stationary relative to the base body, with a bore in which a free end of the threaded rod is rotatably but not axially displaceably mounted, or the second clamping jaw (13, 13') is formed as a clamping jaw which is adjustable relative to the base body, with a through-bore including an internal thread for the threaded rod, wherein the threaded rod is provided with a counter-rotating thread. - having a base body which is connected to the receiving tube, - having a first clamping jaw (12, 12') and a second clamping jaw (13, 13'), wherein the first clamping jaw (12, 12') and/or the second clamping jaw (13, 13') is/are arranged so as to be adjustable in a direction transverse to the longitudinal extension of the safety barrier post (5, 5'), - having an adjustment element for moving the clamping element (4, 4') into a securing position in which the first clamping jaw (12, 12') and the second clamping jaw (13, 13') exert a clamping force (F S) directed transversely to the longitudinal extension of the safety barrier post (5, 5') on the same, and for moving the clamping element (4, 4') into a non-securing position in which the first clamping jaw (12, 12') and the second clamping jaw (13, 13') do not exert a clamping force on the safety barrier post (5, 5'),