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Home / Policy Information / Highway Performance Monitoring System (HPMS) / Chapter 4

Office of Highway Policy Information
March 2014

Field Manual
Chapter 4: DATA REQUIREMENTS AND SPECIFICATIONS

Item 56: Last_Overlay_Thickness (Last Overlay Thickness)

Description: Thickness of the most recent pavement overlay
Use: For pavement modeling purposes
Extent: All paved Sample Panel sections; optional for all other sections beyond the limits of the Sample Panel

 

Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
FE = Full Extent  SP = Sample Panel Sections

 

Coding Requirements for Fields 8, 9, and 10:

Value_Numeric: Code the actual measured value to the nearest 0.5 inch.

Value_Text: No entry required. Available for State Use.

Value_Date: No entry required. Available for State Use.

Guidance: Reporting should be consistent with IRI inventory direction and lane

Values can also be obtained from construction plans for use in the Table.

An overlay is more than 0.5 inch.

 

Item 57: Thickness_Rigid (Thickness Rigid)

Description: Thickness of rigid pavement
Use: For investment requirements modeling to estimate pavement deterioration and loading history and in the cost allocation pavement model
Extent: All paved Sample Panel sections; optional for all other sections beyond the limits of the Sample Panel

Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
FE = Full Extent  SP = Sample Panel Sections

Coding Requirements for Fields 8, 9, and 10:

Value_Numeric: Code the actual measured value to the nearest 0.5 inch.

Value_Text: No entry required. Available for State Use.

Value_Date: No entry required. Available for State Use.

Guidance: The thickness should reflect the last improvement on the section. When an improvement is made, consider all new or redesigned base and pavement materials when determining the appropriate value.

Reporting should be consistent with IRI inventory direction and lane.

Values can also be obtained from construction plans for use in the Table.

Definitions: Refer to the table of codes in Data Item 49 (Surface Type)

- Codes '3,' '4,' '5,' '9,' and '10' are rigid pavements.

- Codes '2' and '6' are flexible pavements.

- Codes '7' and '8' are composite pavements.

For code '9' (Unbonded Jointed Concrete Overlay on PCC Pavement), only the unbounded overlay should be considered and reported for this data item. For code '10' (Bonded PCC Overlay on PCC Pavement), both bonded overlay and underlying rigid pavement surface layer should be considered and reported for this data item.

    

Item 58: Thickness_Flexible (Thickness Flexible)

Description: Thickness of the flexible pavement
Use: For investment requirements modeling to estimate pavement deterioration and loading history and in the cost allocation pavement model
Extent: All paved Sample Panel sections; optional for all other sections beyond the limits of the Sample Panel

Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
       FE = Full Extent         SP = Sample Panel Sections

 

Coding Requirements for Fields 8, 9, and 10:

Value_Numeric: Code the actual measured value to the nearest 0.5 inch.

Value_Text: No entry required. Available for State Use.

Value_Date: No entry required. Available for State Use.

Guidance:

Reporting should be consistent with IRI inventory direction and lane.

Values can also be obtained from construction plans for use in the Table.

Report total thickness of all AC (asphalt) pavement layer(s); if PCC has been overlaid on AC ("white topped") composite, report the AC layer thickness under it; if AC has been overlaid on PCC, report the AC layer thickness on top.

Definitions: Refer to the table of codes in Data Item 49 (Surface Type).

- Codes '3','4', '5', '9', and '10' are rigid pavements.

- Codes '2' and '6' are flexible pavements.

- Codes '7' and '8' are composite pavements.

Item 59: Base_Type (Base Type)

Description: The base pavement type
Use: For pavement modeling purposes
Extent: All paved Sample Panel sections; optional for all other sections beyond the limits of the Sample Panel

Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
       FE = Full Extent        SP = Sample Panel Sections

 

Coding Requirements for Fields 8, 9, and 10:

Value_Numeric: Supply the appropriate code using the following codes:

Code Description Definitions
1 No Base Surface layer is placed directly on subgrade without a subbase
2 Aggregate Non-stabilized granular, consisting of either crushed stone, gravel, recycled asphalt or concrete
3 Asphalt or Cement Stabilized Aggregate base treated with either asphalt or Portland cement
5 Hot Mix AC (Bituminous) Either a new hot-mix asphalt (HMA) layer placed as the base layer or the HMA surface of an old flexible pavement
6 Lean Concrete A Portland cement concrete mixture made with relatively low cement content (typically about 3 sacks/yd)
7 Stabilized Open-graded Permeable Open-graded aggregate treated with either asphalt or Portland cement for stability
8 Fractured PCC Rubblized or crack-and-seated PCC pavement

Value_Text: No entry required. Available for State Use.

Value_Date: No entry required. Available for State Use.

Guidance:

For rigid pavements the base is all layers between subgrade and bottom of concrete surface. For flexible pavements the base is all layers between subgrade and bottom of asphalt concrete layer. If you have several types of base, use the code that best describes the layer immediately below the surface layer.

Reporting should be consistent with IRI inventory direction and lane.

Item 60: Base_Thickness (Base Thickness)

Description: The thickness of the base pavement
Use: For pavement modeling purposes
Extent: All paved Sample Panel sections; optional for all other sections beyond limits of the Sample Panel

Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
FE = Full Extent  SP = Sample Panel Sections

Coding Requirements for Fields 8, 9, and 10:

Value_Numeric: Code the actual measured value to the nearest inch.

Value_Text: No entry required. Available for State Use.

Value_Date: No entry required Available for State Use.

  
Guidance:

For rigid pavements the base is all layers between subgrade and bottom of concrete surface. For flexible pavements the base is all layers between subgrade and bottom of asphalt concrete layer. If there are several types of base, report the total thickness of all base layers

Reporting should be consistent with IRI inventory direction and lane.

Values can also be obtained from construction plans for use in the Table.

   

Item 61: Climate_Zone (Climate Zone)

Description: Climate zone as defined by the 4 LTPP climate zone descriptions
Use: For cost allocation pavement model purposes
Extent: All paved Sample Panel sections; optional for all other sections beyond the limits of the Sample Panel

Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
        FE = Full Extent     SP = Sample Panel Sections

 

Coding Requirements for Fields 8, 9, and 10:

Value_Numeric: Enter the applicable Long Term Pavement Performance (LTPP) climate zone code:

Code Description
1 Wet-Freeze
2 Wet-Non-freeze
3 Dry-Freeze
4 Dry-Non-freeze

 

Value_Text: No entry required. Available for State Use.

Value_Date: No entry required. Available for State Use.

Guidance:

This data item will be populated by FHWA using the map shown in Figure 4.100, if the States do not provide this information.

   

Figure 4.99: LTPP Climate Zone Map

Figure 4.99 is a map the Long Term Pavement Performance (LTPP) Climate Zones, which consists of four regional zones, dry - no freeze, wet - freeze, wet - no freeze, and dry - freeze.

Item 62: Soil_Type (Soil Type)

Description: Soil type as defined by AASHTO soil classes
Use: For pavement modeling purposes
Extent: All paved Sample Panel sections; optional for all other sections beyond the limits of the Sample Panel

 

Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
   FE = Full Extent       SP = Sample Panel Sections

Coding Requirements for Fields 8, 9, and 10:

Value_Numeric: *Enter the applicable AASHTO soil class code:

Code Description
1 Granular (35% or less passing the 0.075 mm sieve) (AASHTO Soil Class A0 through A-3)
2 Fine (Silt-Clay) Materials (>35% passing the 0.075 mm sieve) (AASHTO Soil Class A-4 through A-7)

 

Value_Text: No entry required. Available for State Use.

Value_Date: No entry required. Available for State Use.

Guidance:

This data item will be populated by FHWA if the States do not provide this information.

Item 63: County_Code (County Code)

Description: The County Federal Information Processing Standard (FIPS) code
Use: For identifying the County for which the data is being reported
Extent: All Federal-aid highways

Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural FE FE FE FE FE FE    
Urban FE FE FE FE FE FE FE  
FE = Full Extent           SP = Sample Panel Sections

Coding Requirements for Fields 8, 9, and 10:

Value_Numeric: Enter the three-digit County FIPS code.

Value_Text: No entry required. Available for State Use.

Value_Date: No entry required. Available for State Use.

Guidance: The official (three-digit) codes are defined in the National Institute of Standards and Technology (NIST) FIPS Publication 6-4.

See Appendix J for codes to be used for Alaska, District of Columbia (DC), and Puerto Rico.

Item 64: NHS (National Highway System)

Description: Roadway section that is a component of the National Highway System (NHS)
Use: For analysis and mapping of NHS information
Extent: All roadways that are designated NHS routes (as of December 31st of the applicable data year), excluding ramps

Functional System 1 2 3 4 5 6 7
Int OFE OPA MiA MaC MiC Local
Rural FE** FE** FE** FE** FE** FE** FE**
Urban FE** FE** FE** FE** FE** FE** FE**
FE** = Full Extent wherever data item is applicable      SP = Sample Panel Sections

 

Coding Requirements for Fields 8, 9, and 10:

Data Item Value: Code the value that represents the type of NHS facility as follows:

 

Code Description
1 Non Connector NHS
2 Major Airport
3 Major Port Facility
4 Major Amtrak Station
5 Major Rail/Truck Terminal
6 Major Inter City Bus Terminal
7 Major Public Transportation or Multi-Modal Passenger Terminal
8 Major Pipeline Terminal
9 Major Ferry Terminal

 

Data Item Text: No entry required. Available for State Use.

Data Item Date: Optional. The Month and Year that the NHS section was officially approved.

Guidance:

Code this data item for roadway segments that reside on an official NHS route.
Use Code ‘1’ (Non-connector NHS) to identify STRAHNET connectors.
The States must provide their NHS data to FHWA as part of their annual submittal until directed otherwise by the FHWA Office of Highway Policy Information. Ultimately, the Office of Highway Policy Information will maintain this data item based on official requests for changes to the NHS per the FHWA Office of Planning.
Provided that FHWA assumes the role of maintaining these datasets in the future, the States will be responsible for submitting additions, deletions, and changes to these networks to FHWA for approval, as directed by the procedures outlined in the appropriate sections of Title 23 CFR, U.S.C., and FHWA regulations. Once approved, the appropriate sections of the network(s) will be coded by FHWA with the approval date, at which time the change will become official. These datasets will be available to the States throughout the year for reference or to download, and will be provided to each State at the end of the calendar year, which will serve as the official network for that calendar year.

Item 65: STRAHNET_Type (Strategic Highway Network)

Description: Roadway section that is a component of the Strategic Highway Network (STRAHNET)
Use: For analysis and mapping of STRAHNET information
Extent: All roadways that are designated STRAHNET routes

Functional System 1 2 3 4 5 6 7
Int OFE OPA MiA MaC MiC Local
Rural FE** FE** FE** FE** FE** FE** FE**
Urban FE** FE** FE** FE** FE** FE** FE**
FE** = Full Extent wherever data item is applicable  SP = Sample Panel Sections

Coding Requirements for Fields 8, 9, and 10:

Data Item Value: Code the value that represents the type of STRAHNET facility as follows:

Code Description
1 Regular STRAHNET
2 Connector

 

Data Item Text: Military Base Name (if one exists).

Data Item Date: Optional. The Month and Year that the STRAHNET section was officially approved.

Guidance:

Code this data item for roadway segments that reside on an official STRAHNET route.

The States must provide their STRAHNET data to FHWA as part of their annual submittal until directed otherwise by the FHWA Office of Highway Policy Information. Ultimately, the Office of Highway Policy Information will maintain this data item based on official requests for changes to the STRAHNET per the FHWA Office of Planning.

Provided that FHWA assumes the role of maintaining these datasets in the future, the States will be responsible for submitting additions, deletions, and changes to these networks to FHWA for approval, as directed by the procedures outlined in the appropriate sections of Title 23 CFR, U.S.C., and FHWA regulations. Once approved, the appropriate sections of the network(s) will be coded by FHWA with the approval date, at which time the change will become official. These datasets will be available to the States throughout the year for reference or to download, and will be provided to each State at the end of the calendar year, which will serve as the official network for that calendar year.

Item 66: Truck (National Truck Network)

Description: Roadway section that is a component of the National Truck Network (NN) as defined by 23 CFR 658
Use: For analysis and mapping of NN information
Extent: All roadways that are designated NN routes

Functional System 1 2 3 4 5 6 7
Int OFE OPA MiA MaC MiC Local
Rural FE** FE** FE** FE** FE** FE** FE**
Urban FE** FE** FE** FE** FE** FE** FE**
FE** = Full Extent wherever data item is applicable  SP = Sample Panel Sections

Coding Requirements for Fields 8, 9, and 10:

Data Item Value: Code the value that represents the type of truck facility as follows:

Code Description
1 Section is on the National Network (NN)
2 Other State-designated truck route (optional)

 

Data Item Text: No entry required. Available for State Use.

Data Item Date: Optional. The Month and Year that the National Truck Network section was officially approved.

Guidance:

Code this data item for roadway segments that reside on an official National Network route.

The States must provide their NN data to FHWA as part of their annual submittal until directed otherwise by the FHWA Office of Highway Policy Information. Ultimately, the Office of Highway Policy Information will maintain this data item based on official requests for changes to the NN per the FHWA Office of Planning.

Provided that FHWA assumes the role of maintaining these datasets in the future, the States will be responsible for submitting additions, deletions, and changes to these networks to FHWA for approval, as directed by the procedures outlined in the appropriate sections of Title 23 CFR, U.S.C., and FHWA regulations. Once approved, the appropriate sections of the network(s) will be coded by FHWA with the approval date, at which time the change will become official. These datasets will be available to the States throughout the year for reference or to download, and will be provided to each State at the end of the calendar year, which will serve as the official network for that calendar year.

Item 67: Future_Facility (Future National Highway System)

Description: Roadway section that is a component of the pending National Highway System (NHS), including intermodal connectors
Use: For analysis and mapping of future NHS information
Extent: All

Functional System 1 2 3 4 5 6 7
Int OFE OPA MiA MaC MiC Local
Rural FE** FE** FE** FE** FE** FE** FE**
Urban FE** FE** FE** FE** FE** FE** FE**
FE** = Full Extent wherever data item is applicable  SP = Sample Panel Sections<

Coding Requirements for Fields 8, 9, and 10:

Data Item Value: Code as follows future NHS facilities as follows:

Code Description
1 Un-built NHS section

 

Data Item Text: No entry required. Available for State Use.

Data Item Date: Optional. The Month and Year that the Future NHS section was officially approved.

Guidance:

Code this data item for roadway segments that may ultimately reside (i.e. awaiting FHWA approval) on an official NHS route.

The States must provide their future NHS data to FHWA as part of their annual submittal until directed otherwise by the FHWA Office of Highway Policy Information. Ultimately, the Office of Highway Policy Information will maintain this data item based on official requests for changes to the future NHS per the FHWA Office of Planning.

Provided that FHWA assumes the role of maintaining these datasets in the future, the States will be responsible for submitting additions, deletions, and changes to these networks to FHWA for approval, as directed by the procedures outlined in the appropriate sections of Title 23 CFR, U.S.C., and FHWA regulations. Once approved, the appropriate sections of the network(s) will be coded by FHWA with the approval date, at which time the change will become official. These datasets will be available to the States throughout the year for reference or to download, and will be provided to each State at the end of the calendar year, which will serve as the official network for that calendar year.

Item 68: Maintenance_Operations (Maintenance and Operations)

Description: The legal entity that maintains and operates a roadway
Use: For administrative, legislative, analytical, and national highway database purposes
Extent: All Federal-aid highways that are toll facilities; optional for all other sections

Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural FE FE FE FE FE FE
Urban FE FE FE FE FE FE FE
FE = Full Extent  SP = Sample Panel Sections

Coding Requirements for Fields 8, 9, and 10:

Value_Numeric: Code the level of government that best represents who maintains and operates the highway irrespective of ownership or agreements for other purposes. If more than one code applies, use the lowest numerical value from the following:

Code Description Code Description
1 State Highway Agency 60 Other Federal Agency
2 County Highway Agency 62 Bureau of Indian Affairs
3 Town or Township Highway Agency 63 Bureau of Fish and Wildlife
4 City or Municipal Highway Agency 64 U.S. Forest Service
11 State Park, Forest, or Reservation Agency 66 National Park Service
12 Local Park, Forest or Reservation Agency 67 Tennessee Valley Authority
21 Other State Agency 68 Bureau of Land Management
25 Other Local Agency 69 Bureau of Reclamation
26 Private (other than Railroad) 70 Corps of Engineers
27 Railroad 72 Air Force
31 State Toll Authority 73 Navy/Marines
32 Local Toll Authority 74 Army
40 Other Public Instrumentality (i.e., Airport) 80 Other
50 Indian Tribe Nation    

 

Value_Text: Optional. Enter secondary operator information, if applicable.

Value_Date: No entry required. Available for State Use.

Guidance:

The term "maintenance and operations" covers the preservation and performance of the highway, including surface, shoulders, roadsides, structures, and such traffic-control devices as are necessary for safe and efficient utilization of the highway.

"State" maintained means one of the 50 States, the District of Columbia, or the Commonwealth of Puerto Rico including quasi-official State commissions or organizations;

"County, local, municipal, town, or township" means maintained by one of the officially recognized governments established under State authority;

"Federal" means maintained by one of the branches of the U.S. Government or independent establishments, government corporations, quasi-official agencies, organizations, or instrumentalities;

"Other" means any other group not already described above or nongovernmental organization that maintains the highway.

In cases where maintenance and operations responsibilities are shared between multiple entities, this item should be coded based on the entity that has the larger degree of responsibility for maintenance and operations. Information on additional entities should be entered in Data Field 9 (Value_Text) for this item.

Item 69: Capacity (Capacity)

Description: The capacity of the roadway as estimated by the State or local agency
Use: For investment requirements modeling to calculate capacity, the cost allocation pavement model, and congestion, delay and other analyses
Extent: All Sample Panel Sections
Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
FE = Full Extent  SP = Sample Panel Sections

Coding Requirements for Fields 8, 9, and 10:

Data Item Value: Enter the estimated capacity for a given roadway

Value_Text: No entry required. Available for State Use.

Value_Date: No entry required. Available for State Use.

Guidance:

The capacity of a roadway facility is the maximum reasonable hourly rate at which vehicles can be expected to transverse a point or a uniform section of lane or roadway during a given time period under prevailing roadway, traffic, and control conditions. Reasonable expectancy is that the stated capacity can be achieved repeatedly. The Highway Capacity Manual provides procedures, formulas, graphics, and tables in assessing roadway capacity.

This item should be estimated based on procedures consistent with the Highway Capacity Manual (HCM).

All urban and rural capacity for freeways and other multilane facilities is for the peak direction. If a rural facility has 2 or 3 lanes with one-way operation, it is considered to be a multilane facility for determining capacity. The capacity for rural facilities with 2 or 3 lanes and two-way operation is for both directions.

4.5 Sample Panel Identification Data Reporting Requirements

This section describes the data fields required for reporting the location of the Sample Panel Sections within the State's Table of Potential Samples (T.O.P.S.). Detailed Information on the sampling procedures associated with the T.O.P.S. is contained in Chapter 6.

Fields Required for Sample Panel Identification Reporting Purposes

The fields of information listed in Table 4.6 are to be submitted as part of the Sample Panel Identification dataset which will be stored in the Sections Catalog (discussed in Chapter 3) within FHWA's system.

Table 4.6: HPMS Sample Panel Identification File Structure

  Field Number Field Name
Sample Panel Section 1 Year_Record
2 State_Code
3 Route_ID
4 Begin_Point
5 End_Point
6 Section_Length
7 Sample_ID
8 Comments (Optional)

The next section describes the detailed specifications for the fields identified in Table 4.6, in terms of their Descriptions, Usage, Data Formats, Coding instructions, and Guidance (where applicable) for each Field.

Field 1: Year_Record

Description: The calendar year for which the data is applicable
Use: For identifying the representative year of the data
Data Type: Numeric
Coding: Enter the four digits for the calendar year that the data represents
Guidance: N/A

Field 2: State_Code

Description: The State Federal Information Processing Standard (FIPS) code
Use: For identifying the State for which the data is being reported
Data Type: Numeric
Coding: Enter up to two digits for the State FIPS code. See Appendix C for a complete list of FIPS codes
Guidance: N/A

Field 3: Route_ID

Description: The unique identifier for a given roadway (i.e., route)
Use: For identifying the specific route for which the data is being reported
Data Type: Text
Coding: Enter an alphanumeric sequence consisting of no more than 60 characters
Guidance: The Route ID is to be developed per the States' preference. However, this ID must be consistent with the Route ID schema that is contained in the State's LRS network attribute data

Field 4: Begin_Point

Description: The point of origin for a given section of road
Use: For identifying the beginning point of a section for spatial referencing purposes
Data Type: Numeric
Coding: Enter a decimal value to the nearest thousandth of a mile
Guidance: N/A

Field 5: End_Point

Description: The terminus point for a given section of road
Use: For identifying the ending point of a section for spatial referencing purposes
Data Type: Numeric
Coding: Enter a decimal value to the nearest thousandth of a mile
Guidance: N/A

Field 6: Section_Length

Description: The true length (i.e., measured length) for a given section of road
Use: For analysis and comparison of various data items for apportionment, administrative, legislative, analytical, and national highway database purposes
Data Type: Numeric
Coding: Code the length in decimal format to the nearest thousandth of a mile
Guidance: Refer to guidance provided in Section 4.2 for Data Field No. 7 in the Sections dataset

Field 7: Sample_ID

Description: A unique identifier for the section
Use: For identifying a section that is within the defined limits of the Sample Panel
Data Type: Text
Coding: Enter an alphanumeric sequence consisting of no more than 12 characters
Guidance: N/A

Field 11: Comments (Optional)

Description: Additional information for State use (formerly referred to as the "State Control Field")
Use: For storing supplemental information provided by the States which is used to manage their various databases
Data Type: Text
Coding: This item can be coded as variable text up to 100 characters, in accordance with the State's needs
Guidance: The information provided in this field is not required by FHWA

4.6 FHWA-Coded Items

Within the scope of the Sections data in HPMS, there are data items that either are currently coded by FHWA, or will be at some point in the future. For reference purposes, Table 4.7 lists these items. FHWA will assign default codes to the items shown with a single asterisk (*) if the States do not provide this information. In addition, the items shown with a double asterisk (**) will be coded by FHWA (at some point in the future) based on updates that are provided by the States to FHWA's Office of Planning. Only FHWA-approved updates will be used to code Data Items 64-67.

Table 4.7 FHWA Coded Items

  Item Number Data Item
FHWA Coded Items 61 Climate Zone*
62 Soil Type*
64 National Highway System (NHS)**
65 STRAHNET**
66 National Truck Network**
67 Future Facility**

The next section provides the detailed specifications for the data items identified in Table 4.7.

Item 61: Climate Zone

Description: Climate zone as defined by the 4 LTPP climate zone descriptions
Use: For the cost allocation pavement model
Coding: This will be coded according to the four FHWA Long Term Pavement Performance (LTPP) climate zone descriptions as follows:
Code Description
1 Wet-Freeze
2 Wet-Non Freeze
3 Dry-Freeze
4 Dry-Non Freeze

Item 62: Soil Type

Description: Soil type as defined by AASHTO soil classes
Use: For pavement modeling purposes
Coding: This will be coded AASHTO soil class data

Item 64: NHS

Description: The FHWA-approved NHS, including intermodal connectors, and the year it was approved (optional)
Use: For establishing the official National Highway System
Coding: This item will be coded for all sections that either are located on the NHS or function as NHS connectors to -intermodal facilities, using one of the following codes:
Code Description
1 Not NHS Connector A designated NHS Route
2 NHS Connector to Airport
3 Port Facility
4 Amtrak Station
5 Rail/Truck Terminal
6 Inter City Bus Terminal
7 Public Transportation or Multimodal Passenger Terminal
8 Pipeline Terminal
9 Ferry Terminal

Item 65: STRAHNET

Description: The Strategic Highway Network (used for Department of Defense purposes)
Use: For identifying the STRAHNET system
Coding: This item will be coded using the following codes:
Code Description
1 Regular STRAHNET
2 Connector

Item 66: National Truck Network

Description: Highway sections that comprise the National Truck Network as defined by 23 CFR 658, Appendix A
Use: For freight modeling and analysis
Coding: This item will be coded using the following codes:
Code Description
1 Section is on the National Truck Network
2 Other State designated truck routes

Item 67: Future Facility

Description: The pending (planned/un-built) NHS, including intermodal connectors
Use: For identifying the National Highway System
Coding: This item will be coded using the following code:
Code Description
1 This is an un-built NHS section

4.7 Software-Calculated Items

In addition to the items that will be coded by FHWA, there is a limited group of data items that will be calculated by the HPMS software once the data has been submitted. These items and the extent for which they will be calculated are listed in Table 4.8 below.

Table 4.8: Software Calculated Items

Data Item Extent
Software Calculated Items Volume Group FE  
Expansion Factor   SP
Horizontal Alignment Adequacy   SP*
Vertical Alignment Adequacy   SP*
Weighted Design Speed   SP
Computed Capacity   SP
Volume/Service Flow Ratio   SP

SP = All Sample Panel Sections (as defined by HPMS)
SP* = Some Sample Panel Sections, see Data Item details

The next section provides the detailed specifications for the data items identified in Table 4.8.

FE = Full Extent  SP = Sample Panel Sections

Item Name: Volume Group

Description: A value that is associated with a defined range of values, used to classify an AADT value
Use: For apportionment, administrative, legislative, analytical, and national highway database purposes
Extent: All Federal-aid highways
Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural FE FE FE FE FE FE    
Urban FE FE FE FE FE FE FE  
Coding: This item will be coded based on the reported AADT, using the following codes:
Code Description
1 Under 500
2 500 - 1,999
3 2,000 - 4,999
4 5,000 - 9,999
5 10,000 - 19,999
Code Description
6 20,000 - 34,999
7 35,000 - 54,999
8 55,000 - 84,999
9 85,000 - 124,999
10 125,000 - 174,999
11 175,000 - 249,999
12 250,000 and more

Item Name: Expansion Factor

Description: The ratio of the total length in a volume group to the total sampled volume group length
Use: For expanding sampled data to represent the Full Extent from which the sample is drawn
Extent: All Sample Panel sections
Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
FE = Full Extent SP = Sample Panel Sections
Coding: This item will be calculated and coded using the volume group information in Data Item 1 (Volume Group)
Calculation: Expansion Factor = Total length in the Volume Group
                           Sampled length in the Volume Group

If the expansion factor for a volume group exceeds 100.000, select additional Sample Panel sections from the Full Extent volume group until the expansion factor is reduced to a maximum of 100.000. If there are fewer than three samples in a volume group (minimum requirement) and additional sections are available, select additional samples from the Full Extent volume group.

Chapter 6 contains a description of the standard sample selection and maintenance scheme.

Item Name: Horizontal Alignment Adequacy

Description: The adequacy of horizontal alignment when curve data are not reported
Use: For investment requirements modeling to estimate horizontal alignment deficiencies and for the truck size and weight analyses
Extent: All rural paved Sample Panel sections, unless Data Item 43 (Curves) is coded for the section
Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural   SP SP SP SP      
Urban                
FE=Full Extent SP = Sample Panel Sections 
Coding: This item will be calculated and coded using the following codes:
Code Description
0 Curve data are reported or this item is not required for the section.
1 All curves meet appropriate design standards for the type of roadway.
2 Some curves are below appropriate design standards but all curves can be safely and comfortably negotiated at the prevailing speed limit on the section. The speed limit was not established by the design speed of curves.
3 Infrequent curves with design speeds less than the prevailing speed limit on the section. Infrequent curves may have reduced speed limits for safety purposes.
4 Several curves uncomfortable or unsafe when traveled at the prevailing speed limit on the section or the speed limit on the section is severely restricted due to the design speed of curves.

Item Name: Vertical Alignment Adequacy

Description: The adequacy of vertical alignment when grade data are not reported
Use: For investment requirements modeling to estimate vertical alignment deficiencies
Extent: All rural paved Sample Panel sections unless Data Item 45 (Grades) is coded
Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural   SP SP SP SP      
Urban                
FE = Full Extent SP = Sample Panel Sections 
Coding: This item will be calculated and coded using the following codes:

Code Description
0 Grade data are reported or not required
1 All meet design standards All grades (rate and length) and vertical curves meet minimum design standards appropriate for the terrain.
2 Some meet design standards Some grades (rate and length) and vertical curves are below appropriate design standards for new construction; all grades and vertical curves provide sufficient sight distance for safe travel and do not substantially affect the speed of trucks.
3 Infrequent grades Infrequent grades and vertical curves that impair sight distance or affect the speed of trucks (when truck climbing lanes are not provided).
4 Frequent grades Frequent grades and vertical curves that impair sight distance or severely affect the speed of trucks; truck climbing lanes are not provided.

Item Name: Weighted Design Speed

Description: The design speed weighted by the length of individual horizontal curves and tangents on a section
Use: For investment requirements modeling to calculate capacity and estimate needed capacity improvements
Extent: All Sample Panel sections
Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
FE = Full Extent       SP = Sample Panel Sections
Coding: When curve data are not provided, a default value based upon functional system and facility type will be used, as shown in the following table:
Roadway Type Functional System Code
Rural Urban
1 2 3 4 5 6 1 2 3 4 5 6
Multilane Divided 70 70 70 70 65   70 70 70 60 55 55
Multilane Undivided 70 70 70 70 60   70 70 70 55 45 45
2/3 Lane 70 70 70 65 60   70 65 65 55 45 45

Item Name: Computed Capacity

Description: The capacity of the roadway as estimated by the HPMS software provided that the State has not reported this information
Use: For investment requirements modeling to calculate capacity, the cost allocation pavement model, and congestion, delay, and other analyses
Extent: Sample Panel sections for which capacity data has not been reported by the State
Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
FE = Full Extent           SP = Sample Panel Sections
Coding:

The capacity of a roadway facility is the maximum reasonable hourly rate at which vehicles can be expected to transverse a point or a uniform section of lane or roadway during a given time period under prevailing roadway, traffic, and control conditions. Reasonable expectancy is that the stated capacity can be achieved repeatedly. The Highway Capacity Manual provides procedures, formulas, graphics, and tables in assessing roadway capacity.

This item will be computed and coded based on procedures used in the HPMS software which are consistent with the Highway Capacity Manual (HCM).

All urban and rural capacity for freeways and other multilane facilities is for the peak direction (ensuring capacity from reversible lanes is included). If a rural facility has 2 or 3 lanes with one-way operation, it is considered to be a multilane facility for determining capacity. The capacity for rural facilities with 2 or 3 lanes and two-way operation is for both directions.

The Computed Capacity is only for sample sections which lack State-provided Capacity (Data Item 69) in order to ensure complete data. State-provided capacities are superior estimates because the State has access to more detailed information than is available through HPMS.

Item Name: Volume/Service Flow Ratio (V/SF)

Description: A computed value reflecting peak hour congestion
Use: For investment requirements modeling to estimate needed capacity improvements, in the national highway database, and for congestion, delay, and other data analyses
Extent: All Sample Panel sections
Functional System   1 2 3 4 5 6 7
NHS Int OFE OPA MiA MaC MiC Local
Rural SP SP SP SP SP SP    
Urban SP SP SP SP SP SP SP  
FE = Full Extent       SP = Sample Panel Sections
Coding:

States are not able to override this value, but are encouraged to verify data items that affect this calculation.

If the volume to service ratio is 1.40 or higher, the measurement and coding of items that affect peak capacity should be inspected.

Items that affect capacity (listed from most to least critical) are:

  1. AADT
  2. K-factor
  3. D-factor
  4. Peak Lanes
  5. Through Lanes (primarily for rural 2 and 3-lane roads)
  6. Median Type
  7. Median Width (< or >= 4 ft.)
  8. Percent Green Time

Less significant items that affect capacity are:

  1. Lane Width
  2. Shoulder Width (< or >= 6 ft.)
  3. Peak Percent Combination Trucks
  4. Peak Percent Single-Unit Trucks
  5. Left-Turn Lanes
  6. Right-Turn Lanes
  7. Peak Parking

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