Why It Matters: High‑voltage and limited energy circuits routed too closely can cause cross‑talk, distortion, or packet errors, especially in dense cable trays or congested ceiling spaces. Best Practice: Use separate trays, conduits, or divider systems to isolate voltage classes. The most common method of installing power cables in tunnels is mounting them on metal brackets or cable trays attached to the sides. Cable trays offer numerous advantages, including ease of installation, flexibility, and improved cable management.