Foggy weather warning poster

This image is a poster advertising reliable travel on the Overhead Railway. In 1929, Liverpool had one of the most memorable fogs, resulting in all traffic, road, rail and river transport, grinding to a halt, except for the Liverpool Overhead Railway. The signals used two colour light signals that were still visible even at 600ft and with its reliable train stops drivers felt safe to drive even when they could see virtually nothing so the railway could continue to run during bad weather.