The invention relates to a vehicle restraint system (10) for limiting roadways comprising a base beam (12) which extends along a longitudinal axis (A), rests on a base (U) and, in a view of an orthogonal cross-section along the longitudinal axis (A), tapers upward starting from the base (U). The system further comprises a guide profile (36) which extends along the longitudinal axis (A), is arranged above the base beam (12) and can be or is connected thereto. In order to increase the weight of the vehicle restraint system according to the invention, the base beam (12), in a view of an orthogonal cross-section along the longitudinal axis (A), has a substantially closed profile forming a cavity (26), said cavity (26) being filled with a high-mass filling material (27).