Why can't there be a walk in clinic attached to an emergency medical facility?

At the entrance there is are staff persons trained for triage, who then direct the patient either towards the clinic for non emergency treatment or to the emergency facility if it is more serious in nature.  If, there is an error made in judgement, both facilities are within the same building, but for the most part, better use of the health resources are spent treating patients with the appropriate level of care and staff expertise.