Geometric design of uninterrupted flow facilities is the process by which engineers seek to provide for the needs of a variety of users and vehicle types while minimizing environmental impacts. Uninterrupted flow exists when there are no traffic control devices that interrupt traffic and where no platoons are formed by upstream signals. Examples are freeways, multilane highways, and two-lane highways. Design involves integrating three dimensions: horizontal alignment, vertical alignment, and cross-section. In addition to the design elements, the professional practices of uninterrupted flow facilities include the effect of roadway design on traffic operation and safety as well as signs, markings, and traffic safety devices associated with rural areas