The steel parabolic arch, which acts as a gateway to the town centre for those arriving at the nearby Trinity Street Railway Station, is actually the support for the railway bridge. The old bridge was closed in 2001 as it was judged to be too weak to carrying the amount of traffic using it. The new bridge opened in 2005.
http://happypontist.blogspot.com/2010/04/manchester-bridges-14-newport-street.html - The Happy Pontilist's Blog