In the United States, certain states, particularly in the West, permit semi trucks to pull three trailers, known as long combination vehicles (LCVs). This practice is mainly seen in states like Arizona, Colorado, Idaho, and Nevada, where the roads are expansive and traffic is sparse. Triple trailers are designed for efficiency, allowing trucking companies to transport more freight with fewer drivers and less fuel consumption. While these vehicles can weigh up to 150,000 pounds with permits, they also present unique challenges, such as increased braking distances and difficulties for other drivers trying to overtake them. The mechanics of triple trailers involve using shorter 'pup' trailers, which helps manage their length and weight distribution. Despite the efficiency benefits, safety advocates express concerns over their maneuverability and the potential hazards they pose on the road. Nonetheless, in the vast stretches of the American West, triple trailers have become a common sight, showcasing the balance between freight efficiency and road safety.