Mae astudiaeth Cam 1 WelTAG (Arweiniad ar Arfarnu Trafnidiaeth Cymru) wedi ystyried pob agwedd ar y ffordd rhwng Caergybi a Post House, yn ogystal â ffyrdd cysylltiedig fel coridor yr A494 o Gyfnewidfa Ewloe i Drome Corner, a llwybrau gwyro. Mae wedi ystyried ble a sut orau i wella'r profiad teithio a sut i sicrhau bod cyn lleied o ddigwyddiadau ag y bo modd a bod cerbydau sy'n torri i lawr yn cael cyn lleied o effaith â phosibl.
The WelTAG Stage 1 study has considered all aspects of the road from Holyhead to Post House, associated routes such as the A494 corridor from the Ewloe Interchange to Drome Corner and diversion routes.  It has looked at where and how best to improve the travel experience and how to minimise the frequency and impact of incidents and breakdowns.