“Introduction to LTPP InfoPave” video in the home page provides a quick overview of LTPP InfoPave. The "How To…" section in the "Help" module in the navigation bar contains videos that will give an overview of the LTPP program as well as explain the many facets of LTPP InfoPave related to searching, viewing, and accessing LTPP data.
No. The public data release through Standard Data Release (SDR) is only a part of the LTPP data resources.
With LTPP InfoPave, users are provided meaningful and easy access to all LTPP data with the supporting technological applications and tools. Unlike the Standard Data Release, the user needs minimal previous exposure to the LTPP data to find a specific data set. Specifically, the pavement performance database included in the SDR is the same as that in InfoPave, but in InfoPave, it is meaningfully organized for the user with user friendly table and field names and the data expanded to section level to facilitate easy data access. In addition, InfoPave provides access to research documents and ancillary information management system (AIMS) data that supplement the Pavement Performance Database (PPDB) data which were never part of the standard data release (SDR) due to space constraints.
Yes. You can access the latest LTPP Standard Data Release through the Data module. This data can be downloaded in Microsoft Access format. You can choose to download the standard data release by volume or by state.
InfoPave provides access to the pavement performance database (PPDB), ancillary information management system (AIMS) data that supplements the PPDB data, and all the LTPP program research documents. The PPDB and AIMS data and the research documents provided through InfoPave is based on the latest Standard Data Release (SDR 29 January 2015). All data collected under the LTPP program is available through LTPP InfoPave. For any data that you were unable to locate, please submit your request through “Customer Support”.
“Introduction to LTPP InfoPave” video in the home page will provide an overview of the data types and multiple means of exploring and accessing the LTPP data.
If you are not familiar with LTPP, a good point to start is the Search module. In this module, multiple search options such as “Sections” (to find specific LTPP experiment sections), “Data” (to search for specific data in the pavement performance database-PPDB), “Ancillary Data” (to search for Ancillary Information Management System (AIMS) data that supplements the data in PPDB), and “Reports” (to search for the LTPP document for which you are looking). If you are interested in finding specific LTPP sections, you should search under “Sections.” For example, if you search for “unbonded concrete overlay” under the “Sections” category, you will be able to see all of the LTPP sections where an unbonded concrete overlay has been placed. If you click on any of these sections, you will be taken to the “Section Summary Report” where a summary of section location, pavement structure, materials, climate, traffic, and performance is tabulated. Similarly, if you are only looking for LTPP documents and publications related to your search, you can search within the “Reports” category. The search can also be conducted within the Data or Ancillary Data categories to find data corresponding to your keyword.
Once you have searched for a keyword, the search results are classified according to their type. The search key/data type legend indicates what types of results have been listed for your search. If you click on a data field in your search results, you will have access to the complete description page for that specific data field, where you can find information regarding the source of data, the data table, the type and units of the data field, and availability of this data for the LTPP pavement sections. You can also preview and select the data for download from the description page.
Even if you are not familiar with LTPP tables, LTPP InfoPave has multiple features (user-friendly data structure, data prioritization, data customization) that help you to find the desired information. Data Selection and Download is the most frequently used feature within LTPP InfoPave, where data is organized for the user to easily gain familiarization with the various data elements in LTPP and access them for download.
After narrowing down (filtering) your search of LTPP sections using “Find Sections”, you can select your desired tables listed under structure, climate, traffic, and performance class with further applicable sub class. If you check the option “Show Advanced Data Classification”, additional classes (of lower or lesser priority) will also be displayed. Each sub class might be a single or group of tables that together contain the information you need. If you hover over each table title, you will see a description of that table. In addition, in accordance with the filters applied to “Find Sections,” it displays the count of sections for which the table has data. While selecting the data, displaying the count of sections allows the user to know if the data is available for all selected sections. With “Show Advanced Data Classification” selected, you can see the list of the fields within each table and customize it to select only those in which you are interested. The downloaded file will include your data individually by each selected tables (Table Names), a separate list of the tables with their descriptions (Table Reference), a table listing all the included fields and their descriptions (Field Reference), and a table listing all other used codes and their descriptions (Codes Reference).
To efficiently retrieve a large amount of data from a particular table or tables, use the SQL Export feature listed under the “Data” module. This feature also includes sample SQL codes, which you can modify for your needs. An example SQL statement for selecting all the data from MON_FRICTION table is "SELECT * FROM MON_FRICTION". Due to download size constraints, very large SQL queries such as all data from MON_HSS_PROFILE_SECTION table will not execute. It is recommended to download LTPP Standard Data Release to obtain extra-large data sets.
For easy data download, a predefined filtering system is available within various features of LTPP InfoPave such as Map, Data, and Media. On the left hand side of your screen under the “Find Sections” header there are filters for general information, structure, climate, traffic, and performance data that can be used to narrow down the LTPP sections. If you scroll your mouse over each filter, you will see a description that explains how each filter works. The filter selection applied in one feature will be carried across other features while you navigate between them. For example, after selecting the sections that are 25 years old in the Map module, you can go to the data module and download your desired tables for these sections.
Under the data selection and download feature there is “Find” functionality to search for a specific term within the LTPP database. For example, typing the term “modulus” in the Find tab of Data Selection and Download feature will highlight the tables/fields that has the term ‘modulus’ in it. The data selection and download feature is so dynamic that selecting these tables or fields will also narrow down the LTPP sections. As soon as the filtering or selection is applied, the download feature also shows the number of LTPP sections on the top header and the details of tables and fields at the bottom.
There are two useful tools within InfoPave that can assist you to get an overview of any selected LTPP section. The first one is the “Section Summary Report” which tabulates a summary of section location, pavement structure, materials, climate, traffic, and performance data. The second is the “Section Timeline” which provides an overview of the history of each LTPP section. This timeline includes maintenance and rehabilitation treatments as well as materials testing and performance monitoring activities during the lifetime of LTPP sections. Both of these useful tools are available through the Data module. However, you can access them through other hubs as well. For example, after you locate a desired section in the Map module, you can click on the section to access Section Summary Report or Section Timeline.
My LTPP feature can be customized according to every user’s application of LTPP InfoPave. If you frequently use any specific feature within LTPP InfoPave, you can pin that application tile in your user corner (My LTPP). In this way, you will have quick access to your favorite tiles without the need to navigate through all the InfoPave hubs. In order to pin an application, go to your desired module and right click on your favorite tile. An option will be displayed on the top right hand side to pin that tile to My LTPP. Selecting that will add the tile to “My LTPP.” If you decide you don’t need a specific tile in My LTPP anymore, then right click on it. An option will be displayed to remove the tile from “My LTPP.” However, you cannot remove the three default tiles, “My Account”, “My Data Extractions”, and “My Data Bucket” from My LTPP.
Data Pivot feature of LTPP InfoPave provides the dynamic view of LTPP sections displayed as square blocks that are pivoted based on selection (7 currently available) criteria. For example, selecting the climatic region criteria will show the count of sections within each LTPP climatic region. You can also use the filters on the left hand side in order to further narrow down your search. Each square block in the Pivot view represents an LTPP section and by clicking on a square block, you will be able to see the value of each parameter, locate the section on the map, and access the Section Timeline, and the Section Summary Report.
The LTPP program has different levels of data quality (from A through E, where level E data is the highest quality that has passed all the checks). LTPP InfoPave provides access to the same database the LTPP program releases through its Standard Data Release (SDR) which includes data at various levels (A through E). The level of data quality is indicated by the field “Record Status”. The graphics and information displayed on the screens are based on this data.
Once the data is selected and added to data bucket for download using the data selection and download feature, the ‘Data Bucket’ screen provides options such as “Submit Data for Extraction”, “Save”, “Clear”, and “Continue to Data Selection”. Selecting the “Save” option will save the data bucket for extraction later. You can access the saved data buckets (“My Data Buckets”) and downloaded data extractions (“My Data Extractions”) under “My LTPP”. Once you download a data bucket, it will be transferred to the “My Data Extractions” section. My Data Extractions shows the status of each extraction (In Progress or Completed). The completed data extractions can be re-downloaded for up to 7 days. The time to complete the data extraction depends on the data size selected for download and the order in the queue while submitting. You will receive an email notifying the completion of data extraction.
Currently, LTPP InfoPave supports exporting five hundred thousand records in Microsoft Excel and five million records in Microsoft Access. Moreover, when exporting data which exceeds five hundred thousand records, the only download file format available is Microsoft Access format. This constraint is set to limit server resource utilization for data export as well as satisfy the limitation on the number of records supported by Microsoft Excel and Microsoft Access. With this constraint, very large SQL queries (e.g., select * from MON_HSS_PROFILE_ELEVATION_25) will not execute. We recommend downloading LTPP Standard Data Release to obtain extra-large data sets.
Dialup connection speeds vary enormously and depend on a number of factors. A 5 MB file may take up to 14 minutes using a 56k modem. This number does not take under consideration delay times between modems and should only be used as a guide. If you have a digital connection such as Cable modem, DSL, T1, or T3 line, download times will be faster. The website compresses the final file using ZIP technology, which at times can help reduce the amount of time to download.
LTPP InfoPave helps users to stay connected to LTPP community and meaningfully use LTPP data by means of its various features as briefed below.
The website’s “Help” hub has: “Announcements” to read about LTPP news; “How to …” videos to get started with LTPP InfoPave; “Presentations” regarding LTPP data; “Application Samples” to show examples of problem statements and how LTPP InfoPave can be used to solve these problems; “Release Notes” for data release and maintenance updates; “Frequently Asked Questions” which address typical questions for InfoPave; and the “Customer Support” where you can submit your questions/comments.
LTPP InfoPave provide customer support for data and website functionality. If your concerns are related to data, select “Data Support” (addressed through the LTPP customer support services), and if you encounter problems with website functionality, please select “Web Site Support” (addressed through LTPP InfoPave customer services).
There are many other help resources available through LTPP InfoPave such as discussed here. “LTPP 2014 and Beyond” includes the purpose of LTPP program, the status of LTPP program, information about ongoing features of LTPP, and options to improve the current LTPP program. “Site Map” provides access to all of the hubs and tiles within LTPP InfoPave organized according to corresponding hierarchy. “LTPP Team” has information about involved personnel and organizations within the LTPP program. Contact the appropriate personnel using the contact information included in the “Contact Us” tab. “LTPP Professional Network” will help you to connect with LinkedIn network. “About” gives LTPP program overview, and “Section 508 Disclaimer” shows compliance.
When you access LTPP data by location in the Map module, the legend shows the color coding criterion based on the data selection. For example, selecting the pavement age, the legend will indicate what range of age each color is representing. For example, yellow might show pavement sections with lower age values. These color codes are demonstrated in concentric circles on the map. The number at the center shows the count of pavement sections in that area on the map. The color of the circle in the middle represents the minimum data range for the pavements within that group, and the color of the outermost circle indicates the maximum data range for the pavements within that group.
If you zoomed enough to see a pavement section, it will be represented as a balloon shaped pin. The color of this pin represents the range of data on that pavement section.
The LTPP program contains two major experiment types: the General Pavement Studies (GPS) which are comprised of pavement sections constructed before the LTPP program started, and the Specific Pavement Studies (SPS) which are the pavement sections designed and constructed specifically for the LTPP program. Here is a detailed list of the different studies:
The “Find Sections” filtering feature in LTPP InfoPave gives users the option to select sections based on experiment type, state/province, etc. This filtering is available in various features of InfoPave such as Map, Data Selection and Download, Section Summary Report, Pavement Cross-Section Viewer, Manual Distress Survey Viewer, and Media. While using those features, you will be able to apply the “Experiment Type” to define the GPS or SPS experiment and “Location” filters to select the required State/Province.
If you are trying to determine the experiment type of a specific section, you can select the “Section Summary Report” under Data hub and the experiment number is available in the general information header of the report.
The unique identifier for LTPP section consists of a combination of STATE_CODE (2 characters)-SHRP_ID (4 characters) (e.g., 27-0501). The naming convention for SHRP_ID varies based on the experiment type as discussed below:
SPS sections SHRP_ID:
The SPS sections have two SHRP_ID systems; the first system is applicable for SPS-1 to SPS-9 projects and the second system is applicable from SPS-10 going forward.
In the first system, the first character should be 0, A, B, C, etc., depending on how many projects of that type exist in a State (e.g., 0XXX, AXXX, BXXX, etc.). The second character for SPS sites is the experiment number (e.g., 01XX or A1XX for SPS-1 projects consisting of SPS-1 sections). For SPS-3 and SPS-4, the 1st character is always alphabetic starting with A and working through the alphabet depending on the number of projects in a State. For example, SHRP_ID (section ID) A310 means the first project of SPS-3.
There are then additional numbers for sections that were purpose- built for a specific state interest. For example, in the A300 series A310, A320, A330, A340 are all core sections. A311, A321, A341 would all be what are referred to as supplemental sections that were intended to investigate certain features on the sections.
However, a section with a SHRP_ID beginning with a 0 is not always a SPS section. For example, a GPS test section in Texas has a SHRP_ID of 0001. Always check the GPS_SPS field in EXPERIMENT_SECTION table before assuming that a section is an SPS section because of its SHRP_ID.
In the second system, the first character should be A, B, C, etc., where the character “A” is assigned to the first project and all test sections located on that project. The second character is the experiment number, where “A” is for SPS-10 experiment; “B” is SPS-11, and so on with “Z” representing the SPS-35 experiment. The third and fourth positions indicate project id (00) or SPS experiment designated section id (01 to 58)/ supplemental section id (59-99).
GPS sections SHRP_ID:
There are no naming conventions for GPS experiments.
If you know the STATE_CODE and SHRP_ID, you may use the ‘Section’ search feature or the ‘Find Section’ to locate your LTPP section.
As all the table, field, and code information is provided along with the downloaded data, it is no longer necessary for the user to search for this data individually.
If the user is interested in getting the table, field, and codes for all tables in PPDB, it is recommended to download the LTPPTD, LTPPDD, and CODES tables that provide this information using the ‘SQL Export’ feature or using ‘SDR Export’ feature in InfoPave.
Construction Number (CONSTRUCTION_NO) is an event number used to relate changes in pavement structure with other time dependent data elements. CN= 1 when a test section is initially accepted into LTPP and is incremented with each change in the layer structure.
For each maintenance and rehabilitation treatment applied to a test section after the start of monitoring under the LTPP program, the CONSTRUCTION_NO (CN) is incremented in the EXPERIMENT_SECTION table. The codes in the CN_CHANGE_REASON field indicate what type of activity was performed to cause the change in CN (For example, a CN_CHANGE_REASON of 19 represents the application of an asphalt concrete overlay). Please see MAINT_WORK codes for the complete code list of CN_CHANGE_REASON. The field CN_ASSIGN_DATE provides a date when the CN event occurred.
“Pavement Cross-Section Viewer” under “Visualization” hub provides detailed information about the pavement structure of each test section over time. The “Pavement Cross-Section Viewer” presents layer information in a visual and user-friendly format.
“Section Summary Report” under the “Data” hub also provides layer structure information. In this feature, you will find the layer number, layer type, and layer thickness in the “LTPP Section History and Pavement Structure” table under “Data” tab.
The LAB_CODE field is a four digit character field to help users identify where the laboratory is located and who performed the test. Using the STATE_CODE definition, the first two characters represent the State in which the laboratory is located. The third character indicates what laboratory performed the test (see shaded box below) and the fourth character represents the sample’s test number and is sequentially numbered from 1-9, then A-Z.
In the ‘Data’ hub of the InfoPave website, go to the ‘Section Summary Reports’ and select the State/Province and section SHRP ID number that you have in mind. For example, if you select Vermont from the ‘State’ drop-down menu and 50-1002 from the ‘Section’ drop-down menu, the section overview will tell you that this test section belongs to the GPS-1 experiment, and its coordinates are (44.11961, -73.17939). You will also find that it is located in Addison County on US-7 north bound.
Once the sections are filtered in the “Data Selection and Download” feature under “Data” hub, the “Friction” table under the “Surface Characteristics” group will have all the available friction information regarding the filtered sections. In order to make sure you are looking at the complete list of performance tables, check the “Show Advanced Data Classification” option. Then, if you click on “Add to Selection” option, you will be able to preview the data or you can select “Add to Data Bucket” option to download the data.
Once the sections are selected with ‘Find Sections’ in the ‘Data Selection and Download’ feature, under ‘Structure,’ the tables under the ‘Material’ group will have all the available material information regarding the selected sections. In order to make sure you are looking at the complete list of material tables, check the ‘Show Advanced Data Classification’ option.
The recent LTPP data analysis project conducted backcalculation of pavement structural parameters based on all of the falling weight deflectometer (FWD) deflection data collected until 2012. These backcalculated data can be accessed through the Data Selection and Download, SQL Export, and Table Export features.
Please note that some of these data may be absent because some States or Provinces did not keep complete records of maintenance and rehabilitation histories. Any available information can be found in the “Maintenance and Rehabilitation (M&R)” tables under the “Structure” tab in the “Data Selection and Download” feature. In order to make sure you are looking at the complete list of tables, check the “Show Advanced Data Classification” option.
The ‘Climate’ tab of the ‘Data Selection and Download’ feature lists all the climate tables/fields that have all the available climatic information regarding the selected sections. In order to make sure you are looking at the complete list of climate tables, check the ‘Show Advanced Data Classification’ option. You may also choose to narrow down your sections using ‘Find Sections’ before selecting the data to get your desired data set.
While LTPP has no official definition of climate regions for analysis purposes, LTPP InfoPave uses four climatic regions as ‘Wet, Freeze,’ ‘Wet, No-Freeze,’ ‘Dry, Freeze,’ and ‘Dry, No-Freeze’ to classify LTPP sections. The wet/dry regions are defined in terms of average annual precipitation (508 mm/year, 20 inches/year) and freeze/no-freeze regions as a function of average annual freezing index (FI) (83.3 degree-Celsius days). The average annual precipitation and average annual freezing index are computed using the most recent 20 years of data.
The ‘Traffic’ tab of the ‘Data Selection and Download’ feature lists all the traffic tables that have all the available traffic information regarding the selected sections. In order to make sure you are looking at the complete list of traffic tables, check the ‘Show Advanced Data Classification’ option. You may also choose to narrow down your sections using ‘Find Sections’ before selecting the data to get your desired data set.
The ‘Section Summary Reports’ feature under the “Data” hub is the best way to review performance data of an LTPP section. Under the ‘Graphs’ tab of this summary report, you will see graphs of the major pavement performance information as a function of time. If you are interested in downloading the numerical data, you can use the “Go To” feature to go to the ‘Data Selection and Download’ feature in the ‘Data’ hub and select the respective tables under ’Performance.’ In order to make sure you are looking at the complete list of performance tables, check the ‘Show Advanced Data Classification’ option.
Once the sections are selected with ‘Find Sections’ in the ‘Data Selector’ feature, under ‘Performance,’ the ‘JPCP’ tables under the ‘Manual Distress’ group will have all the available faulting information regarding the selected sections.
The efficient way to get FWD data for selected sections is to use the “Data Selection and Download” feature. Once the sections are filtered with ‘Find Sections’, under ‘Performance’ the ‘Deflection Data’ tables will have all the available FWD drop load, drop height, and deflection information regarding the selected sections.
The data files, images, and videos that are part of the LTPP data collection that supplement the Pavement Performance Data Base (PPDB) are called Ancillary Information Management System (AIMS) data. This data is now available for view and download through LTPP InfoPave. The distress images and roadway videos are provided through ‘Media.’ The distress images are also available in ‘Section Timeline.’ The data files (such as M&R, FWD and Profile files) are available for download under ‘Ancillary Data’ of ‘Data’ hub.
In the “Tools" hub, the “LTPP Data as MEPDG Inputs for Local Calibration” feature currently provides the input for all JPCP sections (SPS-2 and GPS-3). The option to provide input for all sections will be considered in the next phase of LTPP InfoPave.
No. The LTPP Pavement Performance Data Base (PPDB) has different levels of data quality (from A through E, where level E data is the highest quality that has passed all the checks). This is indicated by the field “Record Status” in each table. The Ancillary Information Management System (AIMS) data is stored based on the guidelines but do not have this quality check associated with it.
The layer structure information in the Section Summary Report represents the latest existing pavement layers, and this information is displayed using the maximum Construction Number (CN) corresponding to each pavement section.