Which device is primarily used to prevent unauthorized vehicles from entering the work zone?

• A. Platform Equipped Underbridge Crane
• B. Shadow Vehicle
• C. Scaffolds
• D. Boat

Answer: (B)

Controlling access to a work zone is essential for protecting workers and equipment. A shadow vehicle is the device used to prevent unauthorized vehicles from entering the work zone because it provides a highly visible, mobile barrier that follows the work area, signaling drivers to stay out of the restricted space. Its primary role is to deter and delay any vehicle encroachment, helping to create a safe buffer around the crews and equipment. Platform-equipped underbridge cranes are used for lifting and placing materials, not for traffic control. Scaffolds are temporary structures for worker access to elevated surfaces, not for restricting vehicle entry. A boat has no role in road-work zone security. Therefore, the shadow vehicle best serves this purpose.