Arkansas Administrative Code
Agency 229 - Ar Geographic Information System Board prev State Land Information Board
Rule 229.00.18-001 - Revisions to Arkansas Centerline File (ACF) Standard

1. Dual carriageway routes

2. Single carriageway

3. Connector segments

4. Traffic circles

5. Grade separated access ramps

6. At-grade access ramps

7. Frontage roads

8. Highway facilities

Digitizing:

Centerline files intended for incorporation into the ACF program may be produced utilizing heads-up digitizing techniques. Heads-up digitizing methodologies used may include, but are not limited to, point mode, stream mode, spaghetti mode, or increment mode. Heads-up digitizing should be performed utilizing the following standards.

Capture scale should be 1:1,200

Projection - UTM Zone 15

Datum - North American Datum 1983 (NAD83)

Units - Meters

Source - At a minimum, the second Generation Digital Ortho Quarter Quadrangles

(DOQQs) that have verified horizontal accuracies should be used. However, the best available imagery should always be used given that many jurisdictions have acquired their own aerial imagery since the acquisition of the state DOQQs mentioned above.

Best practices should always be adhered to when digitizing features in the ACF vector layer. These shall include, but may not be limited to the following:

1. All linear road features representing public or private roads that have been given a name and left/right range values for addressing purposes should be properly segmented into individual features at intersections representing transportation decision points and snapped to endpoints to ensure proper topology. If an existing road feature is split to create proper segmentation, the left and right addresses ranges should be recalculated to reflect the change in geometry. The exceptions to this would be but are not limited to:

2. When digitizing curves, utilize the minimum number of vertices that will accurately represent the true shape of the road. However, use of arc/node, Bezier curve, or tangent curve tools is not recommended due to the excessive number of vertices the tools create.

3. For single carriageway roads, the actual centerline of the traversable lanes should be digitized. This also applies to connector segments, grade separated access ramps, at-grade access ramps, traffic circles, frontage roads, and highway facilities. Single carriageway roads should be digitized in the direction of increasing address range values as prescribed by the local addressing authority. All one-way access ramps should be digitized in the direction of vehicular travel.

4. For dual carriageway roads, separate linear features should be digitized along the actual centerline of each set of traversable lanes separated by the positive barrier or median. All access ramps should be included. Centerlines should be digitized in the direction of travel and left/right range values created in such a way to enable proper geocoding in the antilog direction.

Edge Matching:

Where roads cross political boundaries, e.g. city, county, or state boundary, the linear centerline feature shall be snapped to the edge of the applicable boundary and properly segmented. The city, county, and state boundaries maintained by the Arkansas Department of Transportation (ArDOT) and the Arkansas GIS Office and available via gis.arkansas.gov should be used as the geometric features to which the road segments are snapped. Where a road centerline is coincident with a political boundary and different jurisdictions are on each side, e.g. a city and a county, a single centerline feature should be used and differences in naming and addressing practices attributable to the different jurisdictions should be accounted for by using the alternate fields.

Global Navigation Satellite System (GNSS):

Centerline files intended for incorporation into the ACF program may be produced utilizing current accepted standards for GNSS data collection.

Technical Practices for Creating ACF Attributes

The following standards apply to the collection and maintenance of the centerline attributes that are intended for incorporation into the ACF program.

Minimum Standards for ACF Attributes:

Table 1

1'federal = maintained by specific federal agencies, e.g. U.S. Forest Service, U.S. Fish and Wildlife Service, U.S. Army Corps of Engineers, National Park Service, etc.

State = interstate highways, US highways, state highways, and any other road maintained by a state government entity

county = road officially accepted into a county road system and maintained as such by a county road department

municipal = road maintained by an incorporated municipality

private = any road or driveway not maintained by a public entity

levee road = road constructed atop a regulated levee under the jurisdiction of a local levee district

public = roads receiving some amount of county maintenance for public use, but not accepted as an official county road

2Each RD_DESIGN value is defined in the "Definition of Terms" section.

3A county may choose to maintain surface type attributes more detailed than "paved" or "unpaved". However, the RD_SURFTYP field will at a minimum carry the "paved" or "unpaved" attribute to meet the all public roads linear referencing system requirement.

4log = log direction, i.e. in the direction of increasing log mile values antilog = antilog direction, i.e. in the direction of decreasing log mile values

*Note: The line in this instance is a linear geospatial theme that represents a centerline. Address ranges are typically established for individual centerline segments so address matching may be performed. Whenever practical, street names and address ranges shall conform to the actual situs addresses assigned.

Typographic Conventions:

The "#" symbol, hyphens or other punctuations shall not be used in any part of centerline attribute files created with the intent to be incorporated into the ACF program.

Directional Prefixes & Suffixes:

Centerline files intended for incorporation into the ACF program shall use directional prefixes and suffixes established by the United States Postal Service. (Refer to Appendix A.) The directional prefixes and suffixes shall be uppercase.

Metadata Identifier:

Centerline files intended for incorporation into the ACF program shall have a metadata identifier that associates (links) the contributed file to its proper metadata. Each segment shall have a metadata code assigned at the state level.

Street Name:

When primary street names are numbers, the numeral shall be used rather than the actual spelling. For example, "1" would be used rather than "First". Names that are made up of numbers shall also include additional characters such as "th", "rd", "st" or "nd", e.g.

"1st", "2nd", "3rd", etc. These characters shall be included in the primary street name field.

Street names shall utilize capital and lower case letters. Common abbreviations are acceptable in the street name. These might include, but are not limited to Dr (Doctor) or Jr (Junior). This will insure the name fits the field length requirements.

In addition to the rules described above, naming conventions for the primary street names in the ACF should in all cases correspond to the actual situs addresses assigned by the local addressing authority. These should also be consistent with the naming conventions used in the situs address point data maintained by the local jurisdiction and with the local Master Street Address Guide (MSAG), if applicable.

Street Type:

Centerline files created with the intent to be incorporated into the ACF program shall use street abbreviations established by the United States Postal Service. The street type shall be composed of upper and lower case characters.

Unique Id:

Each line segment within the Arkansas Centerline File Program shall have a unique

identifier. The unique identifier shall be assigned at the state level.

Additional Considerations

Updates/ Maintenance:

A specific entity shall be identified to insure that the ACF is updated and maintained in a timely manner. Following spatial or attribute updates and/or modifications performed to the ACF shall be submitted to the entity responsible for performing quality control practices.

Quality Control:

Rigorous quality control techniques shall be implemented to insure the ACF has an acceptable horizontal accuracy and attribute integrity is maintained.