WHAT IS THE DIFFERENCE BETWEEN AN ARTERIAL STREET AND A NON-ARTERIAL (LOCAL) STREET?

Federal and State guidelines require that streets be classified based on function. Generally, streets are classified as either arterial streets or non-arterial streets. Cities can also use the designations to guide the nature of improvements on certain roadways, such as sidewalks or street calming devices.

The primary function of arterials is to provide a high degree of vehicular mobility through effective street design and by limiting property access. The vehicles on arterials are often through traffic. Generally, the higher the classification of a street (Principal Arterial) being the highest), the greater the volumes, through movements, length of trips and the fewer the access points. Arterials in Shoreline are further divided into the three classes and are described as follows:

• Principal Arterials have higher levels of local land access controls, with limited driveway access, and regional significance as major vehicular travel routes that connect between cities within a metropolitan area. Examples: Aurora Avenue N, NE 175th Street and 15th Avenue NE • Minor Arterials are generally designed to provide a high degree of intra-community connections and are less significant from a perspective of a regional mobility. Examples: Meridian Avenue N,N/ NE 185th Street and NW Richmond Beach Road • Collector Arterials assemble traffic from the interior of an area/community and deliver it to the closest Minor or Principal Arterials. Collector Arterials provide for both mobility and access to property and are designed to fulfill both functions. Examples: Greenwood Avenue N, Fremont Avenue N and NW Innis Arden Way.

All streets other than arterials are generally designated as non-arterial (local) streets, which provide local accesses. Non-arterial streets include Local Primary Streets and Local Secondary Streets, with Local Primary Streets typically being longer streets that carry higher volumes than Local Secondary Streets.

The classification of a roadway often determines eligibility for grant funding. Typically, granting agencies fund projects only on arterials. Similarly, roadway classification influences the types of traffic improvements the City will construct on a street. For example, arterials are not eligible for traffic calming features and generally are not considered for improvement through the City’s Neighborhood Traffic Safety Program. Shoreline does not typically stripe centerlines on non- arterial (local) streets.

The chart on the reverse of this page describes the typical characteristics of streets in Shoreline.

TYPICAL SHORELINE STREET CHARACTERISTICS

Arterial Streets Non Arterial (Local) Streets Principal Arterial Minor Arterial Collector Arterial Local Primary Local Secondary Street Street Function - Connect cities and - Connect activity - Provide access to - Connect traffic from - Provide local urban centers with centers within the community local secondary accesses minimum delay City services and streets to Arterials - Connect traffic to - Connect traffic to businesses - Accommodate short Interstate system Principal Arterials - Connect traffic from trips to neighborhood - Accommodate long and Interstate Non Arterial Streets destinations and through trips - Accommodate to Minor or Principal - Provide local some long trips Arterials accesses - Accommodate medium length trips Speed Limits 30 – 40 mph 30 – 35 mph 25 – 30 mph 25 mph 25 mph

Daily Volume More than 15,000 7,000 – 20,000 2,000 – 8,000 less than 3,000 less than 3,000 (vehicles per day) Number of Three or more lanes Two or more lanes Two or more lanes One or Two lanes One or Two lanes Lanes Lane striping Pavement markings Pavement markings Pavement markings No centerline striping No centerline striping used to delineate used to delineate used to delineate travel lanes. travel lanes. travel lanes. Transit Buses/transit stops Buses/transit stops Buses/transit stops Buses/transit stops Buses/transit stops allowed allowed allowed not generally allowed not allowed except for short segments Bicycle May contain bicycle May contain bicycle May contain bicycle - Shared lanes can Bike facilities not Facilities lanes, shared lanes lanes, shared lanes lanes, shared lanes be provided specifically provided; or signage or signage or signage - Signs may be may include signed included bike routes

Pedestrian - Sidewalks on both - Sidewalks on both - Sidewalks on both Safe pedestrian Safe pedestrian Facilities sides sides sides access through the access through the - Amenity zones - Amenity zones - Amenity zones use of sidewalks, use of sidewalks, trails, or other means. trails, or other means.