Whenever the governing body of any county is of the opinion that it is necessary to establish or alter the location of a public highway or bridge, or any other person applies to the local governing body therefor, it may appoint five viewers, who shall be resident freeholders of the county, any three of whom may act, to examine such highways or routes and report upon the expediency of establishing or altering the location of such public highway or bridge. In lieu of such viewers, the local governing body may direct the county road engineer or county road manager to examine such highway or route and make such report, and such board may establish or alter such highway or bridge upon such location and of such width and grade as it may prescribe. The right-of-way for any public highway shall not be less than 30 feet wide, except that in any case in which the cost of constructing and maintaining any such highway is to be borne by any individual the right-of-way for such highway may be less than 30 but not less than 15 feet in width. If none of the viewers is an engineer, appointed for the purpose of making survey and map, the local governing body may employ an engineer, if necessary, to assist the viewers.