Went over this , under it and viewed it a couple of years ago brilliant bit of British engineering https://pv.viewsurf.com/958/Viaduc-...XgpqRtjv5n-uFnrERLgQsOooZXks1WD22vnNikIfUi_10
Designed by Norman Foster and Michel Virlogeux, it was built by a company called Effiage a French civil engineering company.