Description. Standard highway guardrails or median barriers can be used as
perimeter vehicle barriers (Figure 29).
A cable guardrail consists of H-beams [2-1/4 inch (5.7-cm) x 4.1 pound/foot (6.1-
kg/m)], spaced at 16 feet (4.9 m) on center, with two or three 3/4-inch (1.9-cm) diameter steel
cables, spaced 8 inches (20 cm) apart. The height at the center cable is 26 inches (66 cm). The
cables should be anchored to a reinforced concrete deadman at 200-foot (61-m) intervals (similar
to Figure 35).
A W-beam guardrail consists of H-beams spaced on 12.5-foot (3.8-m) centers with
steel "W" sections bolted to the H-beam. The height of this guardrail is 27 to 30 inches (68 to 76
A box-beam guardrail consists of H-beams, spaced on 4- to 6-foot (1.2- to 1.8-m)
centers with a 6- by 6-inch (15- by 15-cm) steel tube bolted to the H-beams. The height of this
guardrail is 27 to 30 inches (68 to 76 cm).