Abstract: Disclosed is an apparatus and method for decelerating moving vehicles. A set of two novel pylons is disclosed employing a simple, durable and reliable braking mechanism. Each braking mechanism comprises a spindle assembly including a brake disk and a spool assembly comprising a rotor and two caliper disks adjacent the brake disk. The spool assembly is pivotally mounted on the spindle assembly. As the strap is deployed a ratchet and pawl mechanism fixed to the base of the spindle assembly prevents the spindle assembly from rotating with respect to the spool assembly. The sliding friction between the caliper disks and the brake disk impedes the rotation of the spool assembly and restrains deployment of the strap. After impact, the strap can be rewound via a ratchet nut located on the spool assembly. During rewind the spindle assembly rotates with the spool assembly. An additional embodiment connects a sacrificial barrier between the two pylons mounted to a gantry.