Wheel Stop

Also known as Parking Stop, these stops protect the car and objects behind the stop from being damaged if the car is driven too close.  These wheel stops are often secured to the roadway with simple rebar rods.  The rebars fails quickly as they depend on friction with the asphalt, but the asphalt compresses away from the rebar and loses it holding ability.  

Use SP18 for mild abuse application.  Use SP58 for heavy duty applications.