A guardrail run with a rail is arranged along and substantially parallel to a roadway. The rail is made of consecutively arranged round timber sections with abutting end sections. Each round timber section includes a metal band disposed in a vertical groove extending along the bottom side. The timber sections are releasably attached to posts anchored alongside the roadway. A locking plate having a U-shape configuration with two legs connected by a web overlaps with the ends of the metal bands of two adjacent timber sections. The ends of the metal bands are received between the two legs of the locking plate, thereby coupling the metal bands with one another.