Guardrail

4 clues
Bridge part
Highway barrier
Road safety feature
Highway safety barrier
Similar answers:
Adolescentguard
Aguar
Aguarico
Airguard
Alguardian
Armedguard
Avantguard
Bankguard
Bedrail
Belgradepointguard
Bethouaguard
Blackguard
Boarderguard
Bodyguard
Borderguard
Botanicalguardians
Bumguards
Bumperguard
Castguard
Catchesoffguard