Which type of barricade provides the least level of safety?

Traffic cones provide the least level of safety among the barricades listed. They are primarily designed for temporary traffic control and serve as visual aids to guide drivers and inform them of hazards. However, their lightweight design makes them less effective in both deterring vehicle entries and providing protection compared to more substantial barriers.

Concrete walls offer a robust physical barrier that effectively protects both workers and drivers from entering a work zone, while plastic drums and barrel markers can be more prominent and visible than cones, especially when combined with reflective materials. Therefore, traffic cones, while useful for marking and guiding, lack the physical deterrent effect that enhances safety in a work zone. Their primary function is not to impede vehicle movement but to ensure awareness, which is why they rank lower in terms of safety.