They may help but they aren't really designed for that.
Helmets are designed to limit head injuries when you bang your head on the ground mostly. If you get mauled by a truck or a suv it is unlikely to help much although it will still help if you bang and rebound on it.
Helmets are designed to limit head injuries when you bang your head on the ground mostly. If you get mauled by a truck or a suv it is unlikely to help much although it will still help if you bang and rebound on it.