As a result of the traffic, congestion, and overcrowding of the dock roads, many proposals were made for transport solutions. Rails were laid at Liverpool Docks in 1852, linking the warehouses and docks. Initially horses were used, as locomotives were banned because of the risk of fire. From 1859, passenger services were provided using adapted horse omnibuses; the wheel flanges could be retracted to allow an omnibus to leave the tracks to overtake a goods train. By the 1880s, there was an omnibus service every five minutes.