Abstract: A unitary flexible housing includes a top wall, having first and second contact plates mounted within a housing alarm cavity positioned between the top wall and the bottom wall, wherein a control housing is arranged to effect actuation of an audible alarm upon the first and second contact plates directed in communication relative to one another upon a vehicle directing the contact plates together. A visual alarm is optionally employed. The housing includes a bottom wall, including projecting nodes for effecting a non-skid bottom wall surface.