The external width of a tractor trailer and dry van can vary depending on the specific make and model. However, the typical width of a tractor trailer is 8 feet 6 inches (2.59 meters), while the typical width of a dry van is 8 feet (2.44 meters).
It's important to note that these are just general measurements and the actual width may vary slightly depending on the specific vehicle. Additionally, some jurisdictions may have specific regulations regarding the maximum width of commercial vehicles, so it's important to check the local regulations to ensure compliance.