hard shoulder
noun [ C usually singular ] uk/ˌhɑːd ˈʃəʊl.dər/ us/ˌhɑːrd ˈʃoʊl.dɚ/ (US also shoulder); (Irish English hard margin)
（尤指高速公路旁的）硬路肩，紧急停车处
a hard area at the side of a main road where a driver can stop if there is a serious problem