HPMS Frequently Asked Questions

Background Questions

  1. What is the NTFA?
  2. What is HPMS?

Question Related to Data Requirements

  1. What data is required?
  2. How often is data required?
  3. What kind of traffic data is required?
  4. What minimal length of count is acceptable?
  5. How should the data be sent in?
  6. What format should the data be sent in?
  7. I have a complete file of all traffic counts collected by my Agency, do I need to separate out only the NTFA data or can I send my complete file?
  8. How do I export traffic count data from RoadSoft?
  9. What is the difference between an ADT and an AADT?
  10. MDOT collecting traffic counts - Outline

Question Related to Road Segmentation

  1. What/Where are the count locations and NTFA segmentation (Traff_ids)?
  2. How are the traff_id/segment Maintained?
  3. What if there are multiple count locations within one NTFA segment?
  4. What if our traffic count program does not collect on all the NTFA segments?

Other Questions

  1. How will I know what is being submitted to the FHWA?
  2. How can I access any counts MDOT has collected?
 

Basic Background Questions

  • What is the NTFA?

The Non-Trunkline Federal Aid (NTFA) program was created to meet the additional requirement of FHWA's Highway Performance Monitoring System (HPMS) to obtain count based data to create Annual Average Daily Traffic (AADT) volumes on all non-trunkline federal aid roads.

  • What is HPMS?

Highways Performance Monitoring System (HPMS)

The HPMS program is a national level highway information system that contains data on the extent, condition, performance, use, and operating characteristics of the nation's highways. This data is used extensively at the federal level in the analysis of highway system condition and performance; but more importantly in the equitable appropriation of Federal Highway dollars and in support of federal efforts to secure increased transportation funding.

U.S. Code of Federal Regulations Title 23 Part 500.203 sets the general requirements for the state's data collection program. It directs that each state develop and implement a Traffic Monitoring System for Highways program on all roads receiving federal funds. MDOT is required to expand the HPMS traffic data collection effort to include all federal aid roads.

Question Related to Data Requirements

  • What data is required?
      1. Count based traffic volume data (Hourly counts, ADTs, or AADT's) on all Federal Aid roads.
      2. The year the traffic data was collected.
      3. Length of count: 24 hr, 48 hr, seven day etc.
      4. Location of the count: Road name and description, or Pr and PR milepoint, or Road name with Latitude and Longitude.
  • How often is data required?

Three or six year cycle based upon the type of road.

      • Three year: Sample, National Highway System (NHS), and Principal Arterials
      • Six year: All non sample road segments that are federal aid eligible are not being collected on the three year count cycle.
  • What kind of traffic data is required?

Sample and NHS: classification count

Principal Arterials and Non Sample: volume count

  • What minimal length of count is acceptable?

24 hours

  • How should the data be sent in?

Data may be submitted electronically (multiple formats supported), manual upload to MDOT's Traffic Database Management System (TDMS), or a digital data transfer (if supported).

  • What format should the data be sent in?
      • If you are using RoadSoft to manage your traffic count data, the software does allow you to export a shape file that includes the data required (instructions below).
      • If you are a MS2 user, there are two ways to submit data:
        • Created an export from your MS2 system with the appropriate data elements
        • Coordinated with MDOT to pair system data locations for an Agency-to-Agency data transfer
      • If do not use either of the above:
        • Manual upload count data into MDOT's MS2 system (inquire for acceptable formats and process)
        • Digitally send data files to MDOT. Acceptable files include, excel, csv, dbf, shapefile, pdf, etc.
          Contact Edward Potter at PotterE@michigan.gov for specifics.
  • I have a complete file of all traffic counts collected by my Agency, do I need to separate out only the NTFA data or can I send my complete file?

A complete file may be sent if location information is included (PR, MP, Latitude/Longitude).

  • How do I export traffic count data from RoadSoft?

Exporting RoadSoft data:

      1. In RoadSoft, open your map layer
      2. On the left hand side, in point layers, click in the road layer box (it will grey out)
      3. Go to the top left hand corner of screen, right click on file, go down to export. Right click on export, then choose export layer to shape file.
      4. An export layer to shape file screen appears.
      5. Under include, check the following boxes:
        • AADT
        • AADT Year
        • ADT
        • ADT Date
        • BMP
        • EMP
        • NFC
        • Ownership
        • PR_Name
        • PRNO
      6. Click in save export data to and save file.
      7. Click in shapefile name, name file: traffic data.
      8. Click on the export button.

Please indicate the length of time the counts were set for. This can be a summary, i.e. "All counts were set for 24 hours."

  • What is the difference between an ADT and an AADT?

ADT (Average Daily Traffic): The 24 hour average daily traffic.

The total traffic volume during a given time period (more than a day and less than a year) divided by the number of days in that time period.

AADT (Annual Average Daily Traffic): The 24 hour average daily traffic (ADT) to which factors (seasonal, monthly, daily) have been applied.

  • MDOT collecting traffic counts on your roads - outline
    • The NTFA program operates on both three and six year cycles so you will be contacted to coordinate the collection of the NTFA traffic data as the cycles re-occur, corrections are made, or new locations are added.
    • Once the site/count locations in your area have been scheduled, the MDOT field staff assigned to complete the traffic study will notify you minimally one-two weeks prior to setting the traffic monitoring equipment on the roads.
    • The traffic volume counts will be taken with pneumatic tubes and portable traffic counters.
    • Typically the traffic counts will be taken for 48 hours between Monday and Thursday of the week.
    • The traffic data will be processed and will be available on MDOT's Traffic monitoring web site (http://mdotnetpublic.state.mi.us/tmispublic/)normally within six to eight weeks after the data has been collected. M
      Instructions for traversing the website are at located in the Other Questions section of this page.
    • Annually you will receive the Annual Average Daily Traffic (AADT) report of the traffic MDOT collected for your review prior to being sent to the HPMS coordinator for FHWA submittal. The AADT will be created from the 24 hour average of the traffic study using a factor of 1 unless otherwise directed by the Agency. If bad data is identified it will be removed and the location will be scheduled to be re-counted.

Question related to road segmentation

  • What/Where are the Count Locations and NTFA segmentation?

Count locations are maintained in MDOT's Traffic Database Management System (TDMS) developed by MS2. The traffic segmentation is maintained in a geographic information system (GIS ) environment, Roads and Highways, hosted by ESRI. MDOT worked with regional planning organizations (RPOs) and metropolitan planning organizations (MPOs) to group segments with similar traffic patterns to form traffic segments. The traffic segments are based on traffic patterns and not on routes, functional classification, or PR.

  • How are traffic segments maintained?

Traffic segments are updated throughout the year using ESRI's Roads and Highways platform to incorporate appropriate segment changes. On an annual basis the NTFA segments are reviewed for data integrity and accuracy of grouped traffic patterns.

  • What if there are multiple count locations within one NTFA segment?

If there are multiple count locations on one traffic segment MDOT has a process to manually review these locations and if deemed appropriate will create an average from the counts to populate the traffic segment. If the counts are deemed out of tolerance than MDOT will reject these counts and will average the remaining accepted counts, if more than one, or use the one count location that is paired to the traffic segment.

  • What if our traffic count program does not collect on all the NTFA segments?

MDOT staff has been allocated to collect the uncollected. Once the "don't count" locations are identified I will work with you to coordinate MDOT staff collecting on your roads. The data collected will be made available to you. You may also choose to add these count locations to your traffic count program, but it is not required.

Other Questions

  • How will I know what is being submitted to the FHWA?

The end date for the HPMS submittal to the FHWA is June 15th. MDOT finalizes the previous year data at the end of summer/early fall. This timeline is dependent on the approval from FHWA of MDOT's HPMS submittal. Once the data is finalized it is made publicly available through FHWA's website or a variety of online publications hosted by MDOT (web maps and data portals).
The traffic counts that come from outside agencies are uploaded into MDOT's TDMS system and are pushed through MDOT's QA/QC process. All approved counts will be used for MDOT's annual submittal.

  • How can I access any counts MDOT has collected?

To attain traffic data that either MDOT has collected or has received from other collecting agencies, please go to MDOT's Traffic Monitoring webpage. This site includes a brief overview of MDOT's traffic collection programs and provides all of the necessary resources to view, print, or download any and all of the traffic data MDOT has available. In addition, documentation is also provided for navigating MDOT's traffic data.