Pa ystyriaeth y mae Llywodraeth Cymru wedi'i rhoi i adeiladu twnnel i ddarparu trydedd ffordd o groesi'r Fenai?
Wedi'i ateb gan Y Dirprwy Weinidog Newid Hinsawdd | Wedi'i ateb ar 15/11/2022
A tunnel was considered as part of the WelTAG Stage 2 options selection study but discounted due to the significant level difference between the A55 carriageway and the Menai Strait meaning the tunnel would need to be approximately 5.5km long. The environmental impact due significant areas of land needed for the construction of the tunnel and connecting link roads, large volumes of materials to be excavated and disposed, unsuitability of a tunnel for active travel and very low benefits to cost ratio compared to a bridge solution were also reasons to discount the tunnel option.