Convention (norm) States and in Germany that motorists drive on the right side of the road, whereas in New Zealand and the United Kingdom motorists drive on the left. The standardization of time is a human convention based on the solar cycle or calendar. The extent to which justice is conventional (as opposed to natural or objective) is historically an important debate among philosophers. The nature of conventions has raised long-lasting philosophical discussion. Quine, Davidson, and David Lewis published influential writings on the subject. Lewis's account of convention received an extended critique in Margaret Gilbert's "On Social Facts" (1989), where an alternative
Level crossings in the United Kingdom signed on 14 March 1957, and automatic and automated crossings came into use, with the first automatically operated level crossing commencing operation at Spath near Uttoxeter in Staffordshire in May 1961. Automatic half-barrier crossings later came into being after another enquiry abroad in 1963, consisting of a single arm each side of the road, which block only oncoming traffic leaving the exits clear for trapped occupants. Half barriers were considered to have an advantage as they have a lesser closure time and do not require to be interlocked with signals, but cases where impatient motorists have driven around the barriers