TRA Trailers are a type of trailer used to transport goods and materials. They are usually made of aluminum and have a flatbed design. The term 'TRA' stands for 'Transport and Rail Association'. LAS is an abbreviation for 'Load Allocation System', which is a system used to manage the loading and unloading of goods on TRA Trailers. LALA stands for 'Load Allocation and Logistics Automation', which is a software system used to automate the loading and unloading process of TRA Trailers.