What is the correct term for the splices used in rail tracks?

The term used for the splices in rail tracks is indeed referred to as "smooth joints." These joints are designed to facilitate the smooth continuation of the rail line, allowing trains to pass over them without significant disruption. Smooth joints help reduce wear and tear on both the rail cars and the tracks, contributing to safety and comfort during travel.

These joints are typically reinforced to withstand the stresses of train movement and weather conditions. Proper installation of smooth joints is essential for maintaining the integrity of the rail system and ensuring a safe operating environment. Other terms provided do not accurately describe the specific type of splicing used in rail tracks, which is why they are not applicable in this context.