As part of the refurbishment of the A 21 between Schackendorf and Leezen, the crash barriers on both sides of the central reservation and hard shoulder were renewed. The construction section extended a total length of 4,800 m south of Bad Segeberg to just before Leezen. Including the Schwissel junction, 20,800 m of crash barriers were installed.
Products from the MegaRail and Super-Rail family as well as underride protection systems from the Eco-Safe product range were used.
