Which document is essential to carry when operating a vehicle under a Class C non-CDL license in Illinois?

Carrying a valid driver's license is essential when operating a vehicle under a Class C non-CDL license in Illinois. The driver's license serves as the official permission granted by the state to operate a vehicle, demonstrating that the driver has undergone the necessary training and assessment to safely operate a motor vehicle.

While other documents, such as vehicle registration paperwork and proof of vehicle insurance, are also important for compliance with Illinois law, they do not serve the function of authorizing the driver to operate the vehicle. The driver's license is fundamental to proving that the individual is legally permitted to control a motor vehicle on public roads, hence its critical importance when driving in Illinois.