Garrion Bridge is a major crossing of the River Clyde, at the junction of the A71 and the A72 in the Clyde Valley.
Prior to 2002, it consisted of an old stone bridge, which afforded single-file traffic only. Traffic signals allowed traffic to flow in only one direction at a time, and the bridge was notorious for causing congestion in the area. In 2002, a new bridge was constructed adjacent to the original bridge, and adjoining roads were re-aligned. Together, they operate as a one-way pseudo-roundabout with improved traffic flows compared to the previous situation.
Further information about the bridges and the surrounding hamlet of the same name can be found at the Garrion Bridge entry on Wikipedia.