What is arkansas mainlane gantry?

As an AI language model, I do not have current information on the real-time status of Arkansas mainlane gantry. However, gantries are typically steel or concrete structures that span roads and highways, often used for mounting signs, lights, and cameras for traffic monitoring and enforcement. Mainlane gantries are typically found in high-traffic areas on highways and interstates and can contain tolling equipment, HOV lane restrictions, and other traffic management systems. Arkansas, being a state in the United States, most likely has its own set of regulations and requirements for mainlane gantries.