The legislative body shall cause a written report upon the proposed improvement or acquisition to be prepared for it. The legislative body of a county may require the county surveyor or the county road commissioner to procure the required information and prepare the report, and the legislative body of a city may require the city engineer or the superintendent of streets to procure the required information and prepare the report. In lieu of the county surveyor, county road commissioner, city engineer or superintendent of streets, the legislative body of the city or county may employ any competent person to procure such information and prepare the report. The person required to prepare the report shall complete and file the same with the legislative body within one year from the date such person is directed to prepare the report.