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Home >Maine's Transportation Systems >Classification of Highways >Road Classification: What it means to a Municipality

Road Classification: What it means to a Municipality

What is a ‘State Aid Road’?
• What is the difference between an arterial and a collector?
• Can a road classification be changed?

The concepts of ‘Highway Functional Classification’ and ‘State Highway System ’ can be confusing and are easily misinterpreted. The expressions ‘local road’ and ‘townway’ may sound interchangeable and are often used to describe the same road; however, they mean very different things. What is important to realize about these two terms is that the first describes the federal road classification and the second describes the corresponding state system. The difference between the two categorizations is simple: Federal Functional Class (FFC) describes the functionality and geographical characteristics of a road based upon federal guidelines; and, State Highway System identifies which entity (State or local) is responsible for maintenance and capital expenditure of that road.

The proper classification of all roads is important to towns because it ensures that Federal, State, and local highway funds are spent on the proper roads. In addition, Urban-Rural Initiative Program (URIP) funds are calculated using these classifications and systems. The State Highway System also establishes highway and bridge maintenance responsibilities and determine authority on traffic ordinances and other related issues.

What are the Federal Functional Classifications and State Highway Systems?

Functional classification is the process by which public streets and highways are grouped into classes according to the character of service they are intended to provide. Generally, highways fall into one of three broad categories:

  • Arterials serve countywide, statewide or interstate travel, linking cities and large towns to an integrated highway network. As a general rule of thumb, speeds on the arterial system are relatively high, although speeds may be lower through urban areas. Volumes of traffic typically range from thousands to tens of thousands of vehicles per day. Arterials are further divided between principal and minor arterial roads.
  • Collectors link smaller towns, villages, neighborhoods, and major facilities to the arterial network. Traffic is collected from local residential roads and delivered to the nearest arterial. Daily traffic volumes generally range in the thousands. Collectors are divided between rural and urban collector roads. As a further division, rural collectors are divided between major and minor collector roads.
  • Local roads provide direct access to residential neighborhoods, local businesses, agricultural properties and timberlands. Volumes typically range from less than one-hundred to possibly thousands of vehicles per day. Roads not classified as arterials or collectors are considered local roads.

For more information on the Federal Functional Classification of Highways visit our specific page on this subject.

The State Highway System determines maintenance responsibility. The State Highway System is grouped into three categories:

  • State Highways form a system of connected routes throughout the state that primarily serve intra- and interstate traffic. With the exception of compact areas, the MaineDOT has responsibility for the year-round maintenance of state highways. The State Highway category generally corresponds with the federal ‘arterial’ classification.
  • State Aid Highways connect local roads to the State Highway System and generally serve intracounty rather than intrastate traffic movement. With the exception of compact areas, state aid roads are usually maintained by MaineDOT in the summer and by the municipalities in the winter pursant to State Law 23 MRSA 1003. The State Aid Highway category generally corresponds with the federal ‘collector’ classification.
  • Townways are all other highways not included in the State Highway or State Aid Highway classifications that are maintained by municipalities or counties. These roads are classified as federal ‘local’ roads.

How does MaineDOT determine the functionality of a road?

As development occurs and populations shift, the functionality of roads may change. For this reason the MaineDOT has established guidelines, based upon Federal Highway Administration criteria, for the functional classification of all road types. The following guidelines are used to make a distinction between Collector (State Aid) and Local (Townway) Roads:

  • Land Use: How is the land presently being used? Is it being used for business purposes that generate significant amounts of traffic or is it used for agricultural or residential purposes?
  • Relative Annual Average Daily Traffic (AADT): On an average day, how many, what type, and for what purposes are vehicles using this road?
  • Trip Length: Are a majority of travelers using this road for short trips originating or terminating at locations in the local area or as a road to pass through the region?
  • Network Configuration & Continuity: How does this particular road fit within the present road network? Does the present classification of roads in the surrounding geographical area allow for the efficient movement of traffic through the area?
  • Route Spacing: Is this particular road spaced correctly within the geographical area to provide good opportunities for travelers to reach, specific locations on well maintained and safe roadways?

View the complete Maine Department of Transportation's "Rule # 304" on determining the function of roadways, particularly those classifications that are on the dividing line between State and Local responsibility.

In order to qualify for collector status, a road must generally meet at least three of these five criteria and function as a collector on a regional basis. It should also be noted that traffic activity (AADT) accounts for only one of the criteria. Other factors like network configuration, land use, Trip Length, and Route Spacing are given equal consideration during the functional class review of roads.

If a Municipality feels that the function of a road has changed, a written request must be submitted by Municipal Officials to the Commissioner of MaineDOT. If you have any questions on the process you can call Community Services Division at 207-624-3270.


This page last updated on 6/27/13

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