The flyover, looking towards Belfast, carrying High Street/Braeside across the bypass. I have never seen a photograph of the bridge in railway days but I’d guess that it was probably a stone structure. This link Link (Archive Link ) has some interesting information about the town’s railways but not, unfortunately, a shot of the bridge.
Phase 1 of the Comber bypass opened in the 60’s. Phase 2 opened in 2003. Both are built on the line of the old Belfast-Donaghadee railway. It connects the Belfast road to the roads to Killyleagh/Downpatrick and Newtownards.
The Belfast and County Down Railway ran from Queen’s Quay station in Belfast to Castlewellan via Comber, Downpatrick and Newcastle. There were also lines from Comber to Donaghadee via Newtownards, Belfast to Bangor and branches from Ballynahinch Jct to Ballynahinch and Downpatrick to Ardglass. The lines opened between 1848 and 1892. All closed by 1950 except for Castlewellan – Newcastle which survived until 1955 as part of the GNR(I) route from Belfast via Banbridge and the Bangor line which remains open but from Belfast Central.