Byddai Opsiwn D yn sicrhau symud ar ac oddi ar yr A55 i bedwar cyfeiriad, dau tua’r dwyrain a dau tua’r gorllewin, yng nghyffordd 15 tra’n defnyddio trosbont gyda chyffordd-T i’r gogledd o’r A55 a chyffordd a fyddai’n cael blaenoriaeth i’r de o’r gylchfan bresennol. Byddai’r slipffyrdd ar y gogledd yn cael eu codi’n lleol fel y gallai pont fynd dros yr A55.
Option D would provide movement on and off the A55 in 4 directions, 2 eastbound and 2 westbound, at junction 15 by utilising an overbridge with a T-junction to the north of the A55 and a priority junction to the south of the existing roundabout. The slip roads on the north would be raised locally to allow the bridge to pass over the A55.