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192.00.3-4. Technical Practices for Creating ACF Vector Layer geometry

AR ADC 192.00.3-4Arkansas Administrative CodeEffective: June 6, 2018

West's Arkansas Administrative Code
Title 192. Geographic Information Systems Board
Division 00.
Rule 3. Arkansas Centerline File Standard
Effective: June 6, 2018
Ark. Admin. Code 192.00.3-4
192.00.3-4. Technical Practices for Creating ACF Vector Layer geometry
Currentness
ACF Feature Type:
Vector lines shall be used to represent centerlines. The ACF shall “seamlessly” match across jurisdiction boundaries (i.e., cities, counties, etc.). Address ranges shall be organized along the linear feature to support address geocoding. The address ranges shall be stored within the centerline attribute table of the geospatial dataset.
Topology:
The centerline file shall be processed using appropriate GIS procedures to create and maintain accurate topology, if intended for incorporation into the ACF program. In order to eliminate common dangle and intersect topological errors, care should be taken while digitizing to snap the endpoints of line centerline segments to endpoints of other line segments. At a minimum the following topology rules should be adhered to:
Image 1 within 192.00.3-4. Technical Practices for Creating ACF Vector Layer geometry​
Image 2 within 192.00.3-4. Technical Practices for Creating ACF Vector Layer geometry​
Inclusion of Specific Geometric Elements:
In order to support the development and ongoing maintenance of the all public roads linear referencing system, otherwise known as the All Roads Network Of Linear Referenced Data (ARNOLD, http://www.fhwa.dot.gov/policyinformation/hpms/arnold.cfm), geometric elements representing particular road design types should be digitized in the ACF vector layer. Practices for digitizing these elements can be found in the subsequent Digitizing section.
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:
a. Where the local jurisdiction digitizes driveways for location purposes and does not name or range them for addressing.
b. Where two road centerline features intersect and do not represent a transportation decision point, e.g. an overpass or underpass where direct travel between the roads is not possible. Centerlines should not split (segmented) at these locations.
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.

Credits

Adopted June 6, 2018.
Current with amendments received through February 15, 2024. Some sections may be more current, see credit for details.
Ark. Admin. Code 192.00.3-4, AR ADC 192.00.3-4
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