Better than nothing? Safety barriers in construction zones principles and practice

Safety barriers have limited capability to contain and redirect even when installed in a manner that is fully consistent with testing, manufacturer specifications and first principles. Design tolerances for criteria such as impact speed, vehicle type/mass, and impact angles are finite. Crash testing is limited and only covers idealised setup conditions. Such conditions are rarely mimicked in roadwork construction zones for a variety of reasons.
When modified or installed incorrectly, they can fail to protect workers, as well as creating hazards to the public from features such as incorrect end terminals, unconnected longitudinal units, and various improvised configurations.
The author’s observations are that minor and significant safety barrier compromises are extremely common in construction zones. This paper shows a sample of common system design/installation issues, discusses design principles and practical installation considerations, and examines how well these are communicated within easily available literature for practitioners.