Route Number Designations

In Maine, there are two route numbering systems used on thousands of miles of public roads.  One is the US Route Numbering system and the second is the State Route Numbering system. These numbered routes exist on the Federal and state highway systems with a couple minor exceptions.  However, not all State roads have a route number on them.

US Route Numbering System

The US Route Numbering system primarily exists on the National Highway System (NHS) and other arterial highways in Maine and the criteria can be found here.  They are governed by the American Association of State Highway Transportation Officials (AASHTO).

Whenever a change is needed on these routes, an application has to be submitted by MaineDOT to AASHTO for review and approval.  The list of US Routes in Maine can be found here. Signs are typically a black number on a white shield on a rectangular sheet.

State Route Numbering System

The State Route Numbering system exists on many other miles of arterials and collector roads across the state and the criteria can be found here. They are governed solely by MaineDOT. The current system has evolved over many decades and there are many overlaps and redundancies across the system. Some roads have one number on them while others may have up to 4 numbers on them simply because they intersect as they pass through Maine towns and cities. Whenever a change is needed on these routes, MaineDOT simply makes the change but usually after some public comment. The list of State Routes can be found here. Signs are typically a black number on a white background on a rectangular sheet.