A safety barrier comprises a plurality of posts spaced from each other and disposed adjacent to a roadway, each post having a cross section defined in part by a web and a pair of legs extending therefrom. Additionally, each post has one slot formed in the web of the post extending from an upper end of the post. A first cable and a second cable are releasably engaged with and supported by the posts and disposed within each slot between the respective legs of each post. A third cable and a fourth cable are each coupled to an exterior surface of the posts. The posts and the first, second, third and fourth cables cooperate to prevent a vehicle from leaving the roadway.