How many kinds of special vehicles are there?

Special vehicles are divided into four categories according to their uses. The following is the specific introduction of special models: 1. Special vehicles 1: oil tankers, steam tankers and liquid tankers. 2. Special vehicles II: special water purification vehicles, tank cars except special vehicles I, and various special vehicles used for obstacle clearing, sweeping, cleaning, lifting, loading and unloading (excluding dump trucks), lifting, mixing, digging, bulldozing, refrigeration and heat preservation. 3. Special vehicle III: All kinds of special motor vehicles equipped with fixed special instruments and equipment for professional monitoring, fire fighting, money transport, medical treatment, television broadcasting, etc. 4. Special vehicle IV: container tractor.