From Longman Dictionary of Contemporary Englishguardrailguard‧rail /ˈɡɑːd-reɪl $ ˈɡɑːrd-/ noun [countable] 1 DHa bar that is intended to prevent people from falling from a bridge, cliff etc2 TTC American English a bar that is intended to prevent cars from going off the road in an accident SYN crash barrier British English
Examples from the Corpus
guardrail• The bridge, with its low concrete guardrails, was about ten yards ahead.• They were also checking the condition of guardrails on the M62 highway above, from which the Land Rover plunged.• I tagged his car, which, in turn, tagged the guardrail and flipped over.• Jazzbeaux held on to the guardrail of the landing, and struggled to control her equilibrium. 