Fire crews were called at 10.51am to a fire in the area and have cordoned off the headland stretch of the road in both directions from J17 with the A547 (Conwy Morfa) to J16A Glan-Yr-Afon Road (Dwygyfylchi).
North Wales Police have reported that the incident is an electrical fire.
Queues are already stretching back to Llandudno Juction and Glan Conwy Westbound and Penmaenmawr eastbound. The Sychnant Pass road is also gridlocked due to drivers trying to avoid the road closure
Police are urging drivers to observe the red ‘X’ on the gantry signs and not to try and travel through.
They have also warned drivers not to u-turn if they are caught in the gridlock or to reverse up slip roads against the flow of traffic.
Queues are already stretching back to Llandudno Juction and Glan Conwy Westbound and Penmaenmawr eastbound as emergency crews continue to work on the scene.