What is the purpose of using a plastic sleeve where loop wire crosses a joint?

Using a plastic sleeve where loop wire crosses a joint primarily serves the purpose of protecting the wire from damage. When loop wire is installed in areas where it can be subjected to movement or potential abrasion at joints, a plastic sleeve helps shield the wire from wear and tear that could lead to short circuits or failures in the loop detection system.

This protective measure is especially important because loop wires are often involved in detecting vehicle presence at intersections or in parking areas, and any damage to the wire can compromise the functionality of the system, leading to increased maintenance costs and disruptions in service. The use of a sleeve ensures that the integrity of the loop wire is maintained over time, safeguarding against environmental factors and physical stress.

In contrast, while reducing installation costs might seem beneficial, it's not the primary function of the plastic sleeve; the priority is ensuring the durability and longevity of the wire. Concerns regarding aesthetics or future upgrades are also not relevant to the primary purpose of the sleeve, which is fundamentally focused on protection.