In 1846, the British Parliament passed the Gauges Act that established as the "standard gauge" for Britain. After the Gauges Act, most of the railway track laid in Great Britain was to standard gauge. However many minor railways, both public and industrial, were built to narrower gauges. These lines either followed local traditions or were built in locations where the smaller size of the railway proved more economical or was simply necessary due to physical limitations such as bridges and tunnels.