Benefit$-$Cost ratio is a method utilized for socio$-$economic evaluation of projects, and is particularly valuable in public project evaluations. Identify the benefit and cost components to be used in this type of evaluation for the projects below: a$)$ Placement of traffic control devices such as road humps and stop signs in local neighborhood. b$)$ Installation of noise barriers on a segment of a highway crossing residential neighborhood. c$)$ Additional lane construction on the collector roadway segment.