A55 and A494 Network Resilience Study: WelTAG Stage 1 (10/2017) and WelTAG Stage 2 reports (6/2021).
Astudiaeth o Gydnerthedd Rhwydwaith yr A55 a'r A494: adroddiadau Cam 1 WelTAG (10/2017) a Cham 2 WelTAG (6/2021).