This field functions in a manner similar to the functional category field. As with arterial class, the user has two choices. For a given arterial, the most likely choice will be made for this field if the current selection is inconsistent. Likewise, after a choice is made for this field, the arterial class will change if necessary to retain consistency. The user can use the space bar to toggle between the choices: Urban, Suburban, Intermediate, and Unknown. Users should review the HCM for characteristics of the choices.