Abstract: A road barrier system with a first barrier forming a hollow container and a second barrier forming a hollow container is disclosed, the first and second barriers being configured with alternating structures to permit the barriers to mate. The alternating structures may be located on opposed end walls of the respective barriers and may be configured as alternating half-moon projections and recesses. The mating may permit up to 30 degrees of deflection. Also disclosed are molds for making such barriers, where the molds include a base mold, a female mold, and a male mold, and the base mold may be coupled with either of the female or male molds to create a road barrier mold having features particular to either the female mold or the male mold.