A performance specification is a type of specification that defines the standards that the product or service must be able to meet. Together with functional specifications, performance specifications are output specifications, as the focus is on what the answer needs to be, rather than how the answer should be designed. For example, a government roads authority would traditionally design a new highway including input specifications for the design, materials and method of construction. An alternative would be to provide the contractor with performance specifications for elements of the build, like skid resistance and then allow the contractor to evaluate various solutions and implement the most suitable solution, according to the specifications. See also Specification.