Chapter 12.51 COUNTY ROAD CLASSIFICATION

Chapter 12.51
COUNTY ROAD CLASSIFICATION

Sections:

12.51.010 Classification of roads.

The applicable standards shall be determined by the location (urban or rural areas), function (county, private or exempt private), functional classification (arterial, collector or access) and projected traffic volumes and land use patterns. Terrain (flat, rolling, mountainous) will also enter into standards related to design speed and maximum grade. (Ord. TLS 09-11-49E (Exh. B) (part): Ord. TLS 07-04-30B Exh. B (part): Ord. TLS 04-02-30B Exh. A (part))

12.51.020 Classification definitions.

A. Location. A primary determination of the applicable portions of these standards that must be used is based on the location of the proposed road or street construction or improvement. In most cases, the following will govern whether rural, urban or city road standards will apply.

1. Rural. A rural location is defined as that area not within a federally designated urban or urbanized area or a designated urban growth area as established by Douglas County under the Growth Management Act. Appropriate maps showing the boundaries are available from the Douglas County department of transportation and land services.

2. Urban. An urban location is defined as that area within a federally designated urban or urbanized area or a designated urban growth area as established by Douglas County under the Growth Management Act. Appropriate maps showing the boundaries are available from the Douglas County department of transportation and land services.

3. Other Urban Standards. Other urban standards shall apply to all road and street construction in an area subject to an interlocal agreement between the city and the county to use that city’s road and street standards.

B. Function.

1. County Roads. County roads are those that are continuously open to general public travel and have been accepted by the county into the county road system. Roads and streets that are dedicated to the public shall become county roads upon completion of the construction to county standards, acceptance of the completed construction by the county engineer, and approval of the final plat or other instrument as appropriate by the county. All others must be put on the county road system by means of the road establishment process as specified in Chapter 36.81 RCW and be constructed to county standards for public roads.

2. Private Roads. Private roads are all roads not designated as public or county roads and not open to general public travel.

3. Exempt Private Roads. An exempt private road is a private road, exempt from compliance with Douglas County road standards. The purpose of an exempt private road is for locating and addressing a building site. An exempt private road is not designated as a public or county road and is not open to the general public.

C. Functional Classification—General.

1. Rural Classifications. All county roads in rural areas are classified as rural local access, rural collector (major and minor), rural minor arterial or rural major arterial. New roads and streets and any modifications to existing connector or frontage roads that may be required as a condition of development approval shall meet the minimum design requirements for rural roads as specified in these standards. Different standards will apply depending upon the forecasted traffic volumes and functional classification. Appropriate maps showing the functional classifications are available from the Douglas County department of transportation and land services.

2. Urban Classification. All county roads in urban areas are classified as urban local access, urban collector, urban minor arterial or urban principal arterial. New roads and streets and any modifications to existing connector or frontage roads that may be required as a condition of development approval shall meet the minimum design requirements for urban roads as specified in these standards, provided however, local access roads outside of urban growth areas yet within a federal urbanized area may use a rural standard. Different standards will apply depending upon the functional classification. Appropriate maps showing the functional classifications are available from the Douglas County department of transportation and land services.

D. Functional Classification—Descriptions.

1. Principal Arterial (Urban and Rural). Principal arterials permit traffic flow through and between cities and towns and between major elements of the urban areas. They are of great importance in the regional transportation system as they interconnect major traffic generators, such as central business districts and regional shopping centers, to other major activity centers and carry a high proportion of the total area travel on a minimum of roadway mileage. Principal arterials frequently carry important intra-urban as well as inter-city bus routes.

Many principal arterials are fully or partially access controlled facilities emphasizing the through movement of traffic. Within the category are (a) interstates; (b) other freeways and expressways; and (c) other principal arterials. Spacing of principal arterials may vary from less than one mile in highly developed central business areas to five miles or more in sparsely developed urban fringes and rural areas. Principal arterials generally comprise five to ten percent of the urban system and two to four percent of the rural road miles.

2. Minor Arterial (Urban and Rural). Minor arterials collect and distribute traffic from principal arterials to lesser-classified streets, or allow for traffic to directly access their destination. In urban areas, they serve secondary traffic generators such as community business centers, neighborhood shopping centers, multiple residence areas, and traffic from neighborhood to neighborhood within a community. Urban bus routes generally follow these facilities. Access to land use activities is generally prohibited. Such facilities are usually spaced under two miles apart in urban fringes and in core areas can be spaced one-eighth to one-half mile apart. In sparsely populated areas of our rural counties, minor arterials may be widely disbursed or nonexistent. Rural minor arterials, in conjunction with rural principal arterials, are spaced at such intervals that all developed areas of the state are within a reasonable distance of an arterial highway. Rural minor arterials are expected to provide for relatively high overall travel speeds with minimal interference to through movement. Rural minor arterials generally comprise four to eight percent of the system; whereas, in urban areas they generally comprise ten to fifteen percent.

3. Collectors (Urban). Urban collectors provide for land access and traffic circulation within residential neighborhoods and commercial and industrial areas. They distribute traffic movements from such areas to the arterial system. One-half mile spacing is common in more developed areas. Collectors do not handle long through trips and are not continuous for any great length. They generally account for five to ten percent of the total street system.

4. Collectors (Rural). Rural collector roads are classified as major collectors and minor collectors. These routes generally serve travel of primarily intra-county rather than statewide importance and constitute those routes on which (regardless of traffic volume) predominant travel distances are shorter than on arterial routes. Consequently, more moderate speeds may be typical. Rural collectors, both major and minor, generally constitute twenty to twenty-five percent of the rural road miles.

Rural major collectors provide service to any county seat not on an arterial route; to larger towns not directly served by an arterial; and to other traffic generators of equivalent intra-county importance, such as consolidated schools, shipping points, parks, important agricultural areas, etc. Major collectors link these places with nearby larger towns or cities or with routes of higher classification and serve the more important intra-county travel corridors.

Rural minor collectors should be spaced at intervals, consistent with population density, to collect traffic from local roads and bring all developed areas within a reasonable distance of a collector road. Furthermore, minor collectors provide service to the remaining smaller communities and also link the locally important traffic generators with their rural hinterland.

5. Local Roads and Streets (Rural and Urban). All public roads and streets, not otherwise classified as an arterial or collector, comprise the local access system. These roadways primarily serve local needs for access to adjacent lands, travel over relatively short distances, and connections to collectors or other higher systems. Local urban streets offer the lowest level of mobility and usually contain no bus routes. Service to through traffic movement is deliberately discouraged. Local streets usually account for sixty-five to eighty percent of the urban system. In rural areas, the local roads generally comprise sixty-five to seventy-five percent of the road miles.

E. Terrain. Terrain is a basis for further classification of geometric requirements.

1. Flat terrain is that condition where roadway sight distances, as governed by both horizontal and vertical restrictions, are generally long or could be made to be so without construction difficulty or major expense. The slope of the existing terrain is from zero percent to and including five percent.

2. Rolling terrain is that condition where the natural slopes rise above and fall below the roadway grade line consistently. Normal roadway alignment is restricted by occasional steep slopes. The slope of the existing terrain is from five percent to and including fifteen percent.

3. Mountainous terrain is that condition where longitudinal and transverse changes in the elevation of the ground with respect to a roadway are abrupt and where the roadbed is obtained by frequent benching or side hill excavation. The slope of the existing terrain exceeds fifteen percent.

Terrain classification pertains to the general character of the specific route corridor. Roads in valleys or passes of mountainous areas that have all the characteristics of roads traversing flat or rolling terrain should be classified as flat or rolling. In rolling terrain, trucks reduce their speeds below those of passenger cars on some sections of roadway. Mountainous terrain is responsible for some truck operation at crawl speeds. In cases where the terrain classification is in question, the county engineer shall make the final decision. (Ord. TLS 09-11-49E (Exh. B) (part): Ord. TLS 07-04-30B Exh. B (part): Ord. TLS 04-02-30B Exh. A (part))