TRAFFIC_SO_V

Citation:

Citation Information:

Title: TRAFFIC_SO_V

Spatial Domain:

Bounding Coordinates:

West Bounding Coordinate: -96.632567
East Bounding Coordinate: -90.161030
North Bounding Coordinate: 43.502003
South Bounding Coordinate: 40.385044

Keywords:

Theme:

Theme Keyword Thesaurus: Roget's
Theme Keyword: roads
Theme Keyword: centerline
Theme Keyword: baserecord
Theme Keyword: highway
Theme Keyword: rail crossing

Place:

Place Keyword Thesaurus: none
Place Keyword: Iowa
Place Keyword: Adair county
Place Keyword: Adams county
Place Keyword: Allamakee county
Place Keyword: Appanoose county
Place Keyword: Audubon county
Place Keyword: Benton county
Place Keyword: Black Hawk county
Place Keyword: Boone county
Place Keyword: Bremer county
Place Keyword: Buchanan county
Place Keyword: Buena Vista county
Place Keyword: Butler county
Place Keyword: Calhoun county
Place Keyword: Carroll county
Place Keyword: Cass county
Place Keyword: Cedar county
Place Keyword: Cerro Gordo county
Place Keyword: Cherokee county
Place Keyword: Chickasaw county
Place Keyword: Clark county
Place Keyword: Clay county
Place Keyword: Clayton county
Place Keyword: Clinton county
Place Keyword: Crawford county
Place Keyword: Dallas county
Place Keyword: Davis county
Place Keyword: Decatur county
Place Keyword: Delaware county
Place Keyword: Des Moines county
Place Keyword: Dickinson county
Place Keyword: Dubuque county
Place Keyword: Emmet county
Place Keyword: Fayette county
Place Keyword: Floyd county
Place Keyword: Franklin county
Place Keyword: Fremont county
Place Keyword: Greene county
Place Keyword: Grundy county
Place Keyword: Guthrie county
Place Keyword: Hamilton county
Place Keyword: Hancock county
Place Keyword: Hardin county
Place Keyword: Harrison county
Place Keyword: Henry county
Place Keyword: Howard county
Place Keyword: Humboldt county
Place Keyword: Ida county
Place Keyword: Iowa county
Place Keyword: Jackson county
Place Keyword: Jasper county
Place Keyword: Jefferson county
Place Keyword: Johnson county
Place Keyword: Jones county
Place Keyword: Keokuk county
Place Keyword: Kossuth county
Place Keyword: Lee county
Place Keyword: Linn county
Place Keyword: Louisa county
Place Keyword: Lucas county
Place Keyword: Lyon county
Place Keyword: Madison county
Place Keyword: Mahaska county
Place Keyword: Marion county
Place Keyword: Marshall county
Place Keyword: Mills county
Place Keyword: Mitchell county
Place Keyword: Monona county
Place Keyword: Monroe county
Place Keyword: Montgomery county
Place Keyword: Muscatine county
Place Keyword: O Brien county
Place Keyword: Osceola county
Place Keyword: Page county
Place Keyword: Palo Alto county
Place Keyword: Plymouth county
Place Keyword: Pocahontas county
Place Keyword: Polk county
Place Keyword: Pottawattamie county
Place Keyword: Poweshiek county
Place Keyword: Ringgold county
Place Keyword: Sac county
Place Keyword: Scott county
Place Keyword: Shelby county
Place Keyword: Sioux county
Place Keyword: Story county
Place Keyword: Tama county
Place Keyword: Taylor county
Place Keyword: Union county
Place Keyword: Van Buren county
Place Keyword: Wapello county
Place Keyword: Warren county
Place Keyword: Washington county
Place Keyword: Wayne county
Place Keyword: Webster county
Place Keyword: Winnebago county
Place Keyword: Winneshiek county
Place Keyword: Woodbury county
Place Keyword: Worth county
Place Keyword: Wright county

Direct Spatial Reference Method: Vector
Point and Vector Object Information:

SDTS Terms Description:

Point and Vector Object Count: 319438

Detailed Description:

Entity Type:

Entity Type Label: Captured

Attribute:

Attribute Label: AADT
Attribute Definition: This field indicates the Average Annual Daily Traffic on this road segment. This is applicable for primary, secondard, and municipal roads. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Range Domain:

Range Domain Minimum: 000000
Range Domain Maximum: 999999
Attribute Units of Measure: a vehicle

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: AUTOMOBILE
Attribute Definition: This field indicates the number of automobile on this road segment. This is applicate for only primary roads.
Attribute Definition Source: Iowa ODT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: integer
Enumerated Domain Value Definition: none
Enumerated Domain Value Definition Source: none

Range Domain:

Range Domain Minimum: 0
Range Domain Maximum: 999999
Attribute Units of Measure: each

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: BUS
Attribute Definition: This field indicates the number of buses on this road segment. This is applicable for only primary roads. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: COUNTYEAR
Attribute Definition: This field indicates the year in which the traffic count was taken. This is applicable for primary, secondary and municipal roads.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: integer
Enumerated Domain Value Definition: none
Enumerated Domain Value Definition Source: none

Range Domain:

Range Domain Minimum: 1980
Range Domain Maximum: 1999

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: COUNTYNO
Attribute Definition: County number
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Integer
Enumerated Domain Value Definition: County - the boundary divides two Iowa State counties
Enumerated Domain Value Definition Source: none

Range Domain:

Range Domain Minimum: 1
Range Domain Maximum: 99
Attribute Units of Measure: assigned

Beginning Date of Attribute Values: 1/1/1901
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: ESTIMATE
Attribute Definition: Indicates whether traffic count was estimated
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Y
Enumerated Domain Value Definition: Yes, is an estimate
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: N
Enumerated Domain Value Definition: No, not an estimate
Enumerated Domain Value Definition Source: Iowa DOT base record manual

Range Domain:

Range Domain Minimum: Y
Range Domain Maximum: N
Attribute Units of Measure: alphabetic

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: EXPFACTOR
Attribute Definition: This field is applicable to primary, secondary and municipal road systems and the value will be assigned.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.0000
Range Domain Maximum: 9.9999
Attribute Units of Measure: each

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: HANDT
Attribute Definition: This controls the plotting of the H and T maps.
Attribute Definition Source: Office of Transportation Data
Beginning Date of Attribute Values: 1/1/1999
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: IDNUM
Attribute Definition: Key field auto generated by the system.
Attribute Definition Source: Iowa DOT base record manual
Beginning Date of Attribute Values: 8/1/1999
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: JURISDIC
Attribute Definition: Indicates the jurisdictional responsibility for the segment of road.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: 1
Enumerated Domain Value Definition: Iowa DOT
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 2
Enumerated Domain Value Definition: Iowa DNR
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 3
Enumerated Domain Value Definition: Iowa Dept of SS
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 4
Enumerated Domain Value Definition: Board of Regents
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 5
Enumerated Domain Value Definition: Federal Domain
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 6
Enumerated Domain Value Definition: Local
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 7
Enumerated Domain Value Definition: Iowa National Guard
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 8
Enumerated Domain Value Definition: Other State Lands
Enumerated Domain Value Definition Source: Iowa DOT base record manual

Range Domain:

Range Domain Minimum: 1
Range Domain Maximum: 8
Attribute Units of Measure: assigned

Beginning Date of Attribute Values: 8/1/1999
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: MOTORCYCLE
Attribute Definition: This field indicates the number of motorcycles on this road segment. This is applicable for primary roads. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0
Range Domain Maximum: 99999
Attribute Units of Measure: each

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: MSLINK
Attribute Definition:
This field serves as the link between the data in all the road tables. Does not link to the MSLINK of the structure or rail tables.

Attribute Definition Source: Iowa DOT base record manual
Beginning Date of Attribute Values: 8/1/1999
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: MT5AXLE
Attribute Definition: This field indicates the number of units with a multiple trailer with a total of five axles. This is applicable for only primary roads. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Range Domain:

Range Domain Minimum: 00000
Range Domain Maximum: 99999

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: MT6AXLE
Attribute Definition: This field indicates the number of units with a multiple trailer with a total of six axles. This is applicable for only primary roads. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Range Domain:

Range Domain Minimum: 00000
Range Domain Maximum: 99999

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: MT7AXLE
Attribute Definition: This field indicates the number of units with a multiple trailer with a total of seven axles. This is applicable for only primary roads. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Range Domain:

Range Domain Minimum: 00000
Range Domain Maximum: 99999

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: NINEONEONE
Attribute Definition: 911 Street name
Attribute Definition Source: Iowa DOT base record manual
Beginning Date of Attribute Values: 8/1/1999
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: PICKUP
Attribute Definition: This field indicates the number of pickups and vans on this road segment. This is applicable for only primary roads.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0
Range Domain Maximum: 99999
Attribute Units of Measure: each

Enumerated Domain:

Enumerated Domain Value: integer
Enumerated Domain Value Definition: none
Enumerated Domain Value Definition Source: none

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: RANGENO
Attribute Definition: This field identifies the range location within the county. Example: Code 01= R-1W, 23= R-23W, E1=R-1E, E3=R-3E
Attribute Definition Source: Iowa DOT base record manual
Beginning Date of Attribute Values: 1/1/1901
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: ROADNO
Attribute Definition:
The two-digit road number identifies the road segment which is located in each section of land. West-east roads are assigned odd numbers and south-north roads are assigned even numbers starting at the northwest corner of each section of land working east and south.
Attribute Definition Source: Iowa DOT base record manual
Beginning Date of Attribute Values: 1/1/1901
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: SECTIONNO
Attribute Definition: This field identifies the section number of the township and range location. Code 01 = Section Number 1 etc.
Attribute Definition Source: Iowa DOT base record manual
Beginning Date of Attribute Values: 1/1/1901
Attribute Measurement Frequency: None planned

Attribute:

Attribute Label: SINGLEUNIT
Attribute Definition: This field indicates the number of single units on the road segment. This is applicable for secondary roads only. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: integer
Enumerated Domain Value Definition: none
Enumerated Domain Value Definition Source: none

Range Domain:

Range Domain Minimum: 0
Range Domain Maximum: 99999
Attribute Units of Measure: each

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: SINGMULTTRAILER
Attribute Definition: This field indicates the number of units with either single or multiple trailers on the road segment. This is applicable for secondary roads only. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: integer
Enumerated Domain Value Definition: none
Enumerated Domain Value Definition Source: none

Range Domain:

Range Domain Minimum: 00000
Range Domain Maximum: 99999
Attribute Units of Measure: each

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: ST4AXLE
Attribute Definition: This field indicates the number of units with a single trailer with a total of four axles. This is applicable for only primary roads.The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: integer
Enumerated Domain Value Definition: none
Enumerated Domain Value Definition Source: none

Range Domain:

Range Domain Minimum: 00000
Range Domain Maximum: 99999
Attribute Units of Measure: each

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: ST5AXLE
Attribute Definition: This field indicates the number of units with a single trailer with a total of five axles. This is applicable for only primary roads.The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: integer
Enumerated Domain Value Definition: none
Enumerated Domain Value Definition Source: none

Range Domain:

Range Domain Minimum: 00000
Range Domain Maximum: 99999
Attribute Units of Measure: each

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: ST6AXLE
Attribute Definition: This field indicates the number of units with a single trailer with a total of six axles. This is applicable for only primary roads. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: integer
Enumerated Domain Value Definition: none
Enumerated Domain Value Definition Source: none

Range Domain:

Range Domain Minimum: 00000
Range Domain Maximum: 99999
Attribute Units of Measure: each

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: STATCODE
Attribute Definition: Identifies the road segment as open, legal not open, proposed, or open with no data
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: 0
Enumerated Domain Value Definition: Open
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 1
Enumerated Domain Value Definition: Legal not Open
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 2
Enumerated Domain Value Definition: Proposed
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 3
Enumerated Domain Value Definition: Existing Road with No Data
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 4
Enumerated Domain Value Definition: State border roads
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 5
Enumerated Domain Value Definition: Pending project completion roads
Enumerated Domain Value Definition Source: Iowa DOT base record manual

Range Domain:

Range Domain Minimum: 0
Range Domain Maximum: 5
Attribute Units of Measure: assigned

Beginning Date of Attribute Values: 8/1/1999
Attribute Measurement Frequency: None planned

Attribute:

Attribute Label: STATEROUTE
Attribute Definition:
On Primary roads, the four digit field will always be the state route number with leading zeros. US30 would be 0030. On Secondary roads, the four digit field will be the township number in the first two digits and the range in the next two digits. On municipal and institutional roads the street number is assigned.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0000
Range Domain Maximum: 9999
Attribute Units of Measure: assigned

Beginning Date of Attribute Values: 8/1/1999
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: STATEROUTEPREFIX
Attribute Definition:
This field indicates the index. On primary and institutional roads this field will always be the number '0'. Secondary roads will be the first digit of the township. Municipal roads will be a letter that has been assigned to each city within a county.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: 0
Enumerated Domain Value Definition: Primary or Institutional
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: Numeric
Enumerated Domain Value Definition: First digit of township for secondary
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: Alphanumeric
Enumerated Domain Value Definition: Indicates municipal road
Enumerated Domain Value Definition Source: Iowa DOT base record manual

Beginning Date of Attribute Values: 8/1/1999
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: STATESEGSEQ
Attribute Definition:
State Segment Sequence- On secondary roads this field will be the Section number plus the Road number with leading zero's if applicable. Section 01 and Road Number 02 would be coded 0102. For primary, municipal, and institutional roads, the sequence numbers are used to progressively order road segments by route within a county. The sequence numbers begin at the west or south county line or at the beginning of the route. Breaks in road sections are made on a route at the following points: Intersections with other roads, Intersections with corporation lines, a change in function code, a change in type section, a change in interstate traveled way, interchange ramps, a section line, a change in rural-urban lines, change in surface type,surface width or should width, a traffic volume change, a change in FHWA route number, a change in the maintenance contract on primary roads, a parking change, a rating change of two or more points, a change in federal functional class. On institutional roads, the sequence numbers begin at the entrance to the institution or at thejunction of another road in the institution and does no follow the west and south guidelines.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0000
Range Domain Maximum: 9999
Attribute Units of Measure: assigned

Beginning Date of Attribute Values: 8/1/1999
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: SU2AXLE
Attribute Definition: This field indicates the number of 2 axles single units on this road segment. This is applicable for only primary roads. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: integer
Enumerated Domain Value Definition: none
Enumerated Domain Value Definition Source: none

Range Domain:

Range Domain Minimum: 00000
Range Domain Maximum: 99999
Attribute Units of Measure: each

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: SU3AXLE
Attribute Definition: This field indicates the number of 3 axle single units on this road segment. This is applicable for primary roads. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: integer
Enumerated Domain Value Definition: none
Enumerated Domain Value Definition Source: none

Range Domain:

Range Domain Minimum: 00000
Range Domain Maximum: 99999
Attribute Units of Measure: each

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: SU4AXLE
Attribute Definition: This field indicates the number of 4 axle single units on this road segment. This is applicable for only primary roads. The applicable year is found in the Countyear field.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: integer
Enumerated Domain Value Definition: none
Enumerated Domain Value Definition Source: none

Range Domain:

Range Domain Minimum: 00000
Range Domain Maximum: 99999
Attribute Units of Measure: each

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: SYSCODE
Attribute Definition: Indicates the state assigned system for the segment of road.
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: 1
Enumerated Domain Value Definition: Interstate
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 2
Enumerated Domain Value Definition: U.S. Route
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 3
Enumerated Domain Value Definition: Iowa Route
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 4
Enumerated Domain Value Definition: Farm to Market Route
Enumerated Domain Value Definition Source: Iowa DOT base record manual
Enumerated Domain Value: 5
Enumerated Domain Value Definition: Local Road
Enumerated Domain Value Definition Source: Iowa DOT base record manual

Range Domain:

Range Domain Minimum: 1
Range Domain Maximum: 5
Attribute Units of Measure: assigned

Beginning Date of Attribute Values: 8/1/1999
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: TOWNSHIP
Attribute Definition: Identifies the township location
Attribute Definition Source: Iowa DOT base record manual
Beginning Date of Attribute Values: 8/1/1999
Attribute Measurement Frequency: As needed

Attribute:

Attribute Label: TRAFFICKEY
Attribute Definition: Indicates if the road is designated for truck traffic
Attribute Definition Source: Iowa DOT base record manual
Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Y or N
Enumerated Domain Value Definition: Yes or No
Enumerated Domain Value Definition Source: Iowa DOT base record manual

Range Domain:

Range Domain Minimum: Y
Range Domain Maximum: N
Attribute Units of Measure: Alphabetic

Beginning Date of Attribute Values: 1/1/1980
Attribute Measurement Frequency: As needed