Trucks have spikes on their tires primarily for three reasons: to protect lug nuts from wear and weather damage, to act as a visual warning for other drivers to keep a safe distance, and for aesthetic appeal. These spikes are typically lug nut covers that shield the lug nuts from rust and debris, especially moisture, by flicking it away when the wheel spins. They serve as a noticeable warning sign to discourage other motorists from getting too close, thereby helping to reduce the risk of accidents in truck blind spots. Additionally, many truck drivers use these spikes to give their vehicles a personalized and bold appearance. Despite their intimidating look, these spikes are usually made of aluminum or plastic alloys designed to break off or crumple rather than cause serious damage in a collision. In some states, there are regulations about the size and legality of these spikes, but in general, they are allowed as long as they comply with local vehicle width and safety rules.