Item 56: Last_Overlay_Thickness (Last Overlay Thickness)

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)

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)

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)

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)

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)

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

Item 62: Soil_Type (Soil Type)

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

Item 63: County_Code (County Code)

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

Item 64: NHS (National Highway System)

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)

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)

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)

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)

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)

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.

Field 1: Year_Record

Field 2: State_Code

Field 3: Route_ID

Field 4: Begin_Point

Field 5: End_Point

Field 6: Section_Length

Field 7: Sample_ID

Field 11: Comments (Optional)

Item 61: Climate Zone

Item 62: Soil Type

Item 64: NHS

Item 65: STRAHNET

Item 66: National Truck Network

Item 67: Future Facility

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

Item Name: Volume Group

Item Name: Expansion Factor

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

Item Name: Vertical Alignment Adequacy

Item Name: Weighted Design Speed

Item Name: Computed Capacity

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)

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