What information must be displayed on company vehicles?

The requirement for displaying the Texas ECR (Environmental Compliance Report) number on company vehicles is important for compliance with state regulations, particularly concerning environmental laws and safety standards. This number serves as a unique identifier for companies that deal with hazardous materials or waste. By displaying the ECR number, it helps authorities quickly assess whether the vehicle owner is compliant with regulations regarding environmental safety and compliance policies.

The other options, while potentially relevant in different contexts, do not specifically pertain to the same regulatory needs as the ECR number. For example, an employee identification number is personal and pertains to individual employees rather than regulatory compliance of the vehicle itself. The state registration number is associated with the legal registration of the vehicle but does not convey specific information about the company's compliance with environmental standards. Similarly, the insurance policy number relates to coverage and liability but does not signify compliance with environmental regulations. Therefore, the TX ECR number stands out as the correct choice in this context.