Y ddwy gylchfan ar Gyffyrdd 15 ac 16 yw’r unig ddwy ar brif linell Rhwydwaith Trafnidiaeth Traws-Ewropeaidd Euroroute E22 sy’n rhedeg rhwng Moscow a Dulyn. Mae astudiaethau trafnidiaeth a gynhaliwyd ar hyd yr A55 wedi dangos bod y cylchfannau hyn yn cael effaith negyddol ar y coridor rhwydwaith hwn.
Junctions 15 and 16 are the only 2 roundabouts on the mainline of the Trans-European Transport Network Euroroute E22 which runs between Moscow and Dublin. Transport studies undertaken along the length of A55 have highlighted that these roundabouts have a negative impact on this network corridor.