Heavy Vehicle Travel Information System 

Field Manual 

May 2001 
HEAVY VEHICLE TRAVEL INFORMATION SYSTEM 

CHAPTER 1 

INTRODUCTION 

BACKGROUND

The data from the Heavy Vehicle Travel Information System (HVTIS) will be used to analyze the 

amount and nature of truck travel at the national and regional level. The information would be 

used by FHWA and other DOT administrations to evaluate changes in truck travel in order to 

assess impacts on the highway safety; the role of travel in economic productivity; impacts of 

changes in truck travel on infrastructure condition, and maintaining our mobility while protecting 

the human and natural environment. The increasing dependence on truck transport requires that 

data be available to better assess its overall contribution to the Nation=s well-being. The data will 

allow transportation professionals at the Federal, state and metropolitan levels to make informed 

decisions about policies and plans. 

The majority of States collect vehicle weight data periodically throughout the year using weighin-motion devices and also collect vehicle classification and/or total vehicle volume data 

continuously. To support the HVTIS data needs, the FHWA is requesting that the various State 

Highway Agencies provide monthly reporting of vehicle classification and/or total vehicle 

volume as well as annual reporting of weight data they collect as part of their existing traffic data 

collection programs. 

Through its three stages of development, the HVTIS will provide increasingly detailed heavy 

vehicle data: 

1. National estimates of heavy vehicle highway travel on a monthly basis. 

2. National estimates of axle loadings and highway ton-miles of freight moved each month, 

and 

3. Highway specific estimates of truck volumes and loadings 

TRAFFIC DATA RECORDS

This section contains instructions for coding data in the formats requested by the FHWA. 

The record formats and coding instructions have been developed to provide input to the Heavy 

Vehicle Travel Information System. The HVTIS is supported by the Traffic Volume Trends (TVT) 

system and the Vehicle Travel Information System (VTRIS). 

The TVT system is used to process the continuous traffic volume and vehicle 

classification data and produce a monthly Traffic Volume Trends report. The VTRIS is used to 
process the vehicle classification and truck weight data. Both are microcomputer database 

management systems that validate, summarize, and maintain traffic data. TVT and VTRIS may 

be used by anyone with data in the formats described in this section. They are available for 

downloading on the FHWA website from the Traffic Volume and Truck Weight page at 

<http://www.fhwa.dot.gov/ohim/tvtw/tvtwpage.htm>. 

The data records are divided into four types: station description data, traffic volume data, 

vehicle classification data, and truck weight data. Each type of data has its own individualized 

record format. Specific coding instructions and record layouts are discussed separately for each type 

of data in the next chapters. 

Note that some fields are labeled “critical.” This means that a record cannot be processed by 

TVT or VTRIS without them. All data files described here are ASCII flat files. For character fields 

with missing or inapplicable data, enter blanks. Numbers such as counts should be right-justified 

and filled with leading blanks or zeros unless noted otherwise. For numeric fields with missing or 

inapplicable data, enter blanks or "-1" right-justified. 

Certain data items are common to all four types of records. For example, all records contain 

a six-character station identification. This allows States to use a common identification system for 

all traffic monitoring stations. 

Several fields in the station description record were replaced with fields that are needed to 

tie traffic data to geographic information systems (GIS). This will allow traffic data to be 

overlaid on the National Highway Planning Network (NHPN) and similar systems.
DATA SUBMITTALS TO THE FHWA

Copies of vehicle classification data collected by continuous automatic vehicle classifiers 

should be submitted monthly. In those States that also collect traffic volume data by permanent 

automatic traffic recorders, this data should also be submitted monthly. Both types of data should be 

submitted to FHWA within 20 days after the close of the month for which the data were collected. 

The station description record need only be sent annually or when there is a change. The preferred 

method of transmission is as an attachment to an e-mail message sent to “atrdata@fhwa.dot.gov”. 

Alternatively, diskettes may be mailed to: 

 Federal Highway Administration 

 Travel Monitoring and Surveys Division, HPPI-30 

 400 Seventh Street, SW 

 Washington, D.C. 20590 

 Attention: Traffic Volume Trends 

Annually, each State should submit to the FHWA the vehicle classification and truck weight 

data collected at weigh-in-motion (WIM) sites. Data for the preceding calendar year should be 

submitted by June 15th. More frequent submissions are also acceptable. 

If continuous weigh-in-motion data are available, send up to one week of data per quarter 

(select any week without a holiday). The data should be addressed as follows: 

 Federal Highway Administration 

 Travel Monitoring and Surveys Division, HPPI-30 

 400 Seventh Street, SW 

 Washington, D.C. 20590 

 Attention: Vehicle Travel Information System 

All data should be in the record formats described in this section and edited for 

reasonableness. If the files are large, it is preferable that a compression program such as PKZIP be 

used to condense them. Please provide the name of a contact person and the telephone number in 

case further clarification is necessary. For further information, contact the Travel Monitoring and 

Surveys Division at (202) 366-0175. 
CHAPTER 2 

STATION DESCRIPTION DATA FORMATS 

The Station Description record format is used for all traffic volume, vehicle classification, 

and truck weight monitoring stations. A Station Description file contains one record for each traffic 

monitoring station per year. All fields are considered to be character fields. The optional file 

naming convention is "ssyy.STA", where ss is state postal abbreviation and yy is the last two digits 

of the year. Table 1 summarizes the Station Description record. 

Fields designated as Critical are required for entry into the HVTIS database. 

1. Record Type (Column 1) - Critical

 S = Station description record 

2. FIPS State Codes (Columns 2-3) - Critical

State Code State Code State Code

 Alabama 01 Louisiana 22 Ohio 39 

 Alaska 02 Maine 23 Oklahoma 40 

 Arizona 04 Maryland 24 Oregon 41 

 Arkansas 05 Massachusetts 25 Pennsylvania 42 

 California 06 Michigan 26 Rhode Island 44 

 Colorado 08 Minnesota 27 South Carolina 45 

 Connecticut 09 Mississippi 28 South Dakota 46 

 Delaware 10 Missouri 29 Tennessee 47 

 D.C. 11 Montana 30 Texas 48 

 Florida 12 Nebraska 31 Utah 49 

 Georgia 13 Nevada 32 Vermont 50 

 Hawaii 15 New Hampshire 33 Virginia 51 

 Idaho 16 New Jersey 34 Washington 53 

 Illinois 17 New Mexico 35 West Virginia 54 

 Indiana 18 New York 36 Wisconsin 55 

 Iowa 19 North Carolina 37 Wyoming 56 

 Kansas 20 North Dakota 38 Puerto Rico 72 

 Kentucky 21 

 
Table 1: Station Description Record 

(OMB No. 2125-0587 Expiration 4/30/2004)

Field Columns Width Description

 1 1 1 Record Type 

 2 2-3 2 FIPS State Code 

 3 4-9 6 Station ID 

 4 10 1 Direction of Travel Code 

 5 11 1 Lane of Travel 

 6 12-13 2 Year of Data 

 7 14-15 2 Functional Classification Code 

 8 16 1 Number of Lanes in Direction Indicated 

 9 17 1 Sample Type for Traffic Volume 

10 18 1 Number of Lanes Monitored for Traffic Volume 

11 19 1 Method of Traffic Volume Counting 

12 20 1 Sample Type for Vehicle Classification 

13 21 1 Number of Lanes Monitored for Vehicle Class. 

14 22 1 Method of Vehicle Classification 

15 23 1 Algorithm for Vehicle Classification 

16 24-25 2 Classification System for Vehicle Classification 

17 26 1 Sample Type for Truck Weight 

18 27 1 Number of Lanes Monitored for Truck Weight 

19 28 1 Method of Truck Weighing 

20 29 1 Calibration of Weighing System 

21 30 1 Method of Data Retrieval 

22 31 1 Type of Sensor 

23 32 1 Second Type of Sensor 

24 33 1 Primary Purpose - NEW

25 34-45 12 LRS Identification - NEW

26 46-51 6 LRS Location Point - NEW

27 52-59 8 Latitude - NEW

28 60-68 9 Longitude - NEW

29 69-72 4 SHRP Site Identification - NEW

30 73-78 6 Previous Station ID 

31 79-80 2 Year Station Established 

32 81-82 2 Year Station Discontinued 

33 83-85 3 FIPS County Code 

34 86 1 HPMS Sample Type 

35 87-98 12 HPMS Sample Identifier 

36 99 1 National Highway System - NEW

37 100 1 Posted Route Signing 

38 101-108 8 Posted Signed Route Number 

39 109 1 Concurrent Route Signing 

40 110-117 8 Concurrent Signed Route Number 

41 118-167 50 Station Location
3. Station Identification (Columns 4-9) - Critical

This field should contain an alphanumeric designation for the station where the survey data are 

collected. Station identification field entries must be identical in all records for a given station. 

Differences in characters, including spaces, blanks, hyphens, etc., prevent proper match. Right 

justify the Station ID if it is less than 6 characters. There should be no embedded blanks. 

4. Direction of Travel Code (Column 10) - Critical

Do not combine directions. There should be a separate record for each direction. Whether or not 

lanes are combined in each direction depends on the next field. 

Code Direction

 1 North 

 2 Northeast 

 3 East 

 4 Southeast 

 5 South 

 6 Southwest 

 7 West 

 8 Northwest 

 9 North-South or Northeast-Southwest combined (ATR stations only) 

 0 East-West or Southeast-Northwest combined (ATR stations only) 

5. Lane of Travel (Column 11) - Critical

Either each lane is considered a separate station or all lanes in each direction are combined. 

Code Lane

 0 Data with lanes combined 

 1 Outside (rightmost) lane 

 2-9 Other lanes 

Note: The Station ID, Direction of Travel, and Lane of Travel make up the Station Code. There 

should be one Station Description record per Station Code. Stations can be either by lane or with 

lanes combined by direction, but not both. 

6. Year of Data (Columns 12-13) - Critical

Code the last two digits of the year in which the data were collected. 
7. Functional Classification Code (Columns 14-15) - Critical

 Code Functional Classification

 RURAL 

 01 Principal Arterial - Interstate 

 02 Principal Arterial - Other 

 06 Minor Arterial 

 07 Major Collector 

 08 Minor Collector 

 09 Local System 

 URBAN 

 11 Principal Arterial - Interstate 

 12 Principal Arterial - Other Freeways or Expressways 

 14 Principal Arterial - Other 

 16 Minor Arterial 

 17 Collector 

 19 Local System 

8. Number of Lanes in Direction Indicated (Column 16) 

Code the number of lanes in one direction at the site. Use "9" if there are more than eight lanes. 

9. Sample Type for Traffic Volume (Column 17) 

 T = Station used for Traffic Volume Trends 

 N = Station not used for Traffic Volume Trends 

10. Number of Lanes Monitored for Traffic Volume (Column 18) 

Code the number of lanes in one direction that are monitored at this site. Use "9" if there are more 

than eight lanes. 

11. Method of Traffic Volume Counting (Column 19) 

 1 = Human observation (manual) 

 2 = Portable traffic recording device 

 3 = Permanent automatic traffic recorder (ATR) 

12. Sample Type for Vehicle Classification (Column 20) 

H = Station used for Heavy Vehicle Travel Information System 

 N = Station not used for Heavy Vehicle Travel Information System 

13. Number of Lanes Monitored for Vehicle Classification (Column 21) 

Code the number of lanes in one direction that are monitored for vehicle classification at this site. 

Use "9" if there are more than eight lanes. 

14. Method of Vehicle Classification (Column 22) 
 1 = Human observation (manual) vehicle classification 

 2 = Portable vehicle classification device 

 3 = Permanent vehicle classification device 

15. Algorithm for Vehicle Classification (Column 23) 

Code the type of input and processing used to classify vehicles: 

 A = Human observation on site (manual) 

B = Human observation of vehicle image (e.g., video) 

C = Automated interpretation of vehicle image or signature (e.g., video, microwave, sonic) 

 D = Vehicle length classification 

 E = Axle spacing with ASTM Standard E1572 

 F = Axle spacing with Scheme F 

 G = Axle spacing with Scheme F modified 

 H = Other axle spacing algorithm 

 K = Axle spacing and weight algorithm 

 L = Axle spacing and vehicle length algorithm 

 M = Axle spacing, weight, and vehicle length algorithm 

 N = Axle spacing and other input(s) not specified above 

 Z = Other means not specified above 

16. Classification System for Vehicle Classification (Columns 24-25) 

This indicates the total number of classes in the vehicle classification system. The default value is 

13 which indicates the standard FHWA 13 class system (see Appendix 4-C). The other vehicle 

classification systems are based on the HPMS and the Traffic Monitoring System (TMS) 

documentation. The value that is used will determine the number of count fields needed on the 

Vehicle Classification Record. In the following list the numbers in parentheses are from the FHWA 

13 class system: 

1 = One class: total volume 

2 = Two classes: non-commercial (classes 1-3) and commercial (classes 4-13) vehicles 

3 = Three classes: non-commercial (classes 1-3), single-unit commercial (classes 4-7), combination 

commercial (classes 8-13) vehicles 

4 = Four classes: non-commercial (classes 1-3), single-unit commercial (classes 4-7), single-trailer 

commercial (classes 8-10), multi-trailer commercial (classes 11-13) vehicles 

 5 = Five classes as follows: 

 1 of 5 = two-axle, two or four-tire vehicles (classes 1-3) 

 2 of 5 = buses (class 4) 

 3 of 5 = single-unit trucks (classes 5-7) 

 4 of 5 = single-trailer combination trucks (classes 8-10) 

 5 of 5 = multiple-trailer combination trucks (classes 11-13) 

 13 = FHWA's standard 13 class system (see Appendix 4-C) 

14 = FHWA's 13 class system plus a class 14 (State or vendor defined) 

15 = FHWA's 13 class system plus classes 14 and 15 (State or vendor defined) 

 Other numbers = number of classes (unsupported)
17. Sample Type for Truck Weight (Column 26) 

B = Station used for TMG sample and Strategic Highway Research Program (SHRP) Long Term Pavement 

Performance (LTPP) sample 

L = Station used for SHRP/LTPP sample (but not TMG sample) 

 T = Station used for TMG sample (but not SHRP/LTPP sample) 

 N = Station not used for any of the above 

18. Number of Lanes Monitored for Truck Weight (Column 27) 

Code the number of lanes in one direction that are monitored for truck weight at this site. Use "9" if 

there are more than eight lanes. 

19. Method of Truck Weighing (Column 28)

 1 = Portable static scale 

 2 = Chassis-mounted, towed static scale 

 3 = Platform or pit static scale 

 4 = Portable weigh-in-motion system 

 5 = Permanent weigh-in-motion system 

20. Calibration of Weighing System (Column 29) 

Code the method used to calibrate the weighing system, e.g., comparing weight-in-motion and 

weights from static scales. 

 A = ASTM Standard E1318 

 B = Subset of ASTM Standard E1318 

C = Combination of test trucks and trucks from the traffic stream (but not ASTM E1318) 

D = Other sample of trucks from the traffic stream 

 M = Moving average of the steering axle of 3S2s 

 S = Static calibration 

 T = Test trucks only 

 U = Uncalibrated 

 Z = Other method 

21. Method of Data Retrieval (Column 30) 

 1 = Not automated (manual) 

 2 = Automated (telemetry) 
22. Type of Sensor (Column 31) 

Code the type of sensor used for traffic detection. 

 A = Automatic vehicle identification (AVI) 

 B = Bending plate 

 C = Capacitance strip 

 D = Capacitance mat/pad 

 E = Hydraulic load cells 

 F = Fiber optic - NEW

 G = Strain gauge on bridge beam 

 H = Human observation (manual) 

 I = Infrared 

 K = Laser/lidar 

 L = Inductance loop 

 M = Magnetometer 

 P = Piezoelectric 

 Q = Quartz piezoelectric - NEW

 R = Road tube 

 S = Sonic/acoustic 

 T = Tape switch 

 U = Ultrasonic 

 V = Video image 

 W = Microwave 

 X = Radio wave 

 Z = Other 

23. Second Type of Sensor (Column 32) 

If there are two types of sensors at the station, code the second using the same codes as Type of 

Sensor. Otherwise, code "N" for none. 

24. Primary Purpose (Column 33) – NEW 

This field indicates the primary purpose for installing the station and hence which organization is 

responsible for it and supplies the data. 

E = Enforcement purposes (e.g., speed or weight enforcement) 

I = Operations purposes in support of ITS initiatives 

L = Load data for pavement design or pavement management purposes 

O = Operations purposes but not ITS

P = Planning or traffic statistics purposes 

R = Research purposes (e.g., LTPP) 

25. LRS Identification (Columns 34-45) - NEW

The LRS Identification reported in this item for the station must be the same as the LRS 

identification reported in the HPMS for the section of roadway where the station is located. The 

LRS identification is a 12-character, right justified value. The LRS ID can be alphanumeric, but 

must not contain blanks; leading zeros must be coded. More information concerning the LRS 

may be found in Chapter V of the HPMS Field Manual, Linear Referencing System 
Requirements. 

26. LRS Location Point (Columns 46-51) - NEW

This is the LRS location point for the station. It is similar information to the LRS Beginning Point 

and LRS Ending Point in the HPMS. The KMPT for the station must be within the range of the LRS 

beginning point and LRS ending point for the roadway section upon which the station is located. It 

is coded in kilometers with an implied decimal in the middle: XXX.XXX. 

27. Latitude (Columns 52-59) - NEW

This is the latitude of the station location with the north hemisphere assumed and decimal place 

understood as XX.XXX XXX. 

28. Longitude (Columns 60-68) - NEW

This is the longitude of the station location with the west hemisphere assumed and decimal place 

understood as XXX.XXX XXX. 

29. SHRP Site Identification (Columns 69-72) - NEW

If the site is used in the SHRP/LTPP sample, give the SHRP site ID. 

30. Previous Station ID (Columns 73-78) 

If the station replaces another station, give the station ID that was used previously. 

31. Year Station Established (Columns 79-80) 

Code the last two digits of the appropriate year if known. 

32. Year Station Discontinued (Columns 81-82) 

Code the last two digits of the appropriate year if known. 

33. FIPS County Code (Columns 83-85) 

Use the three-digit FIPS county code (see Federal Information Processing Standards Publication 6, 

"Counties of the States of the United States"). 

34. HPMS Sample Type (Column 86) 

N = No, not on an HPMS standard sample section 

 Y = Yes, on an HPMS standard sample section 

35. HPMS Sample Identifier (Columns 87-98) 
If the station is on an HPMS standard sample section, code the HPMS Sample Identifier per the 

HPMS Field Manual (Item 47). 

36. National Highway System (Column 66) - NEW

 N = No, not on National Highway System 

 Y = Yes, on National Highway System 

37. Posted Route Signing (Column 100) 

This is the same as Route Signing in HPMS Field Manual (Item 22). 

Code Description Code Description

 0 Not signed 5 County 

 1 Interstate 6 Township 

 2 U.S. 7 Municipal 

 3 State 8 Parkway or Forest Route Marker 

 4 Off-Interstate Business Marker 9 None of the above 

38. Posted Signed Route Number (Columns 101-108) 

Code the route number of the principal route on which the station is located. If the station is located 

on a city street, zero-fill this field. This is the same as Signed Route Number in HPMS Field Manual

(Item 24). 

39. Concurrent Route Signing (Column 109) 

Code same as Posted Route Signing for concurrent route if there is one. 

40. Concurrent Signed Route Number (Columns 110-117) 

Code same as Posted Signed Route Number for concurrent route if there is one. 

41. Station Location (Columns 118-167) 

For stations located on a numbered route, enter the distance and direction of the station from the 

nearest major intersecting route or state border or landmark on state road maps. If the station is 

located on a city street, enter the city and street name. Abbreviate if necessary. Left justify. 
CHAPTER 3 

TRAFFIC VOLUME DATA FORMATS 

The Traffic Volume file contains one record for each day of traffic monitoring. All numeric 

fields should be right-justified and zero-filled. Table 2 summarizes the Hourly Traffic Volume 

record. 

Fields designated as Critical are required for entry into the HVTIS database. 

1. Record Type (Column 1) - Critical

 3 = Traffic volume record 

2. FIPS State Code (Columns 2-3) - See chapter 2. - Critical

3. Functional Classification Code (Columns 4-5) - See chapter 2. - Critical

4. Station Identification (Columns 6-11) - See chapter 2. - Critical

This should be right-justified and zero-filled. - Critical

5. Direction of Travel Code (Column 12) - See chapter 2. - Critical

6. Lane of Travel (Column 13) - See chapter 2. - Critical

The code for combined lanes (0) is preferred. 

7. Year of Data (Columns 14-15) - See chapter 2. - Critical

8. Month of Data (Columns 16-17) - Critical

 01 = January 

 02 = February 

 03 = March 

 04 = April 

 05 = May 

 06 = June 

 07 = July 

 08 = August 

 09 = September 

 10 = October 

 11 = November 

 12 = December 
9. Day of Data (Columns 18-19) - Critical

Code the day of the month of data, 01-31. Must correspond to the month of data. 

10. Day of Week (Column 20) - Optional

1 = Sunday 

 2 = Monday 

 3 = Tuesday 

 4 = Wednesday 

 5 = Thursday 

 6 = Friday 

 7 = Saturday 

11-34. Traffic Volume Counted Fields (Columns 21-25, ..., 136-140) 

Enter the traffic volume counted during the hour covered. If the data are missing, code a -1 or 

blanks. 

Field Hour Covered

 11 00:01 am to 01:00 am 

 12 01:01 am to 02:00 am 

 . . 

 . . 

 . . 

 34 11:01 pm to 12:00 midnight 

35. Restrictions (Column 141) 

 0 = no restrictions 

 1 = construction or other activity affected traffic flow 

2 = traffic counting device problem (e.g., malfunction or overflow) - NEW 
Table 2: Hourly Traffic Volume Record

(OMB No. 2125-0587 Expiration 4/30/2004) 

Field Columns Length Description

 1 1 1 Record Type 

 2 2-3 2 FIPS State Code 

 3 4-5 2 Functional Classification 

 4 6-11 6 Station Identification 

 5 12 1 Direction of Travel 

 6 13 1 Lane of Travel 

 7 14-15 2 Year of Data 

 8 16-17 2 Month of Data 

 9 18-19 2 Day of Data 

10 20 1 Day of Week 

11 21-25 5 Traffic Volume Counted, 00:01 - 01:00 

12 26-30 5 Traffic Volume Counted, 01:01 - 02:00 

13 31-35 5 Traffic Volume Counted, 02:01 - 03:00 

14 36-40 5 Traffic Volume Counted, 03:01 - 04:00 

15 41-45 5 Traffic Volume Counted, 04:01 - 05:00 

16 46-50 5 Traffic Volume Counted, 05:01 - 06:00 

17 51-55 5 Traffic Volume Counted, 06:01 - 07:00 

18 56-60 5 Traffic Volume Counted, 07:01 - 08:00 

19 61-65 5 Traffic Volume Counted, 08:01 - 09:00 

20 66-70 5 Traffic Volume Counted, 09:01 - 10:00 

21 71-75 5 Traffic Volume Counted, 10:01 - 11:00 

22 76-80 5 Traffic Volume Counted, 11:01 - 12:00 

23 81-85 5 Traffic Volume Counted, 12:01 - 13:00 

24 86-90 5 Traffic Volume Counted, 13:01 - 14:00 

25 91-95 5 Traffic Volume Counted, 14:01 - 15:00 

26 96-100 5 Traffic Volume Counted, 15:01 - 16:00 

27 101-105 5 Traffic Volume Counted, 16:01 - 17:00 

28 106-110 5 Traffic Volume Counted, 17:01 - 18:00 

29 111-115 5 Traffic Volume Counted, 18:01 - 19:00 

30 116-120 5 Traffic Volume Counted, 19:01 - 20:00 

31 121-125 5 Traffic Volume Counted, 20:01 - 21:00 

32 126-130 5 Traffic Volume Counted, 21:01 - 22:00 

33 131-135 5 Traffic Volume Counted, 22:01 - 23:00 

34 136-140 5 Traffic Volume Counted, 23:01 - 24:00 

35 141 1 Restrictions 
CHAPTER 4 

VEHICLE CLASSIFICATION DATA FORMATS 

The Vehicle Classification file contains one record for each hour with the traffic volume by 

vehicle class. The optional file naming convention is "ssyy.CLA", where ss is state postal 

abbreviation and yy is the last two digits of the year. Table 3 summarizes the Vehicle Classification 

record. 

Fields designated as Critical are required for entry into the HVTIS database. 

1. Record Type (Column 1) - Critical

 C = Vehicle classification record 

2. FIPS State Code (Columns 2-3) - Critical - See chapter 2. 

3. Station Identification (Columns 4-9) - Critical - See chapter 2. 

4. Direction of Travel Code (Column 10) - Critical - See chapter 2. 

5. Lane of Travel (Column 11) - Critical - See chapter 2. 

Note: The Station ID, Direction of Travel, and Lane of Travel make up the Station Code. 

There should be one Station Description record per Station Code. 

6. Year of Data (Columns 12-13) - Critical - See chapter 2. 

7. Month of Data (Columns 14-15) - Critical - See chapter 3. 

8. Day of Data (Columns 16-17) - Critical - See chapter 3. 

9. Hour of Data (Columns 18-19) - Critical

Code the beginning of the hour in which the count was taken: 

 00 = 0:01 a.m. to 1:00 a.m. 

 01 = 1:01 a.m. to 2:00 a.m. 

 . 

 . 

 . 

 22 = 10:01 p.m. to 11:00 p.m. 

 23 = 11:01 p.m. to Midnight 

10. Total Hourly Volume (Columns 20-24) 
This numeric field is the total traffic volume for the hour. The total volume is needed because some 

vehicles might not be classified, in which case the sum of the class counts would not equal the total 

volume. If the total volume is not collected, leave this field blank or put “-1" (for missing data). 

The following class count fields are numeric fields with the traffic volume by vehicle class for each 

hour of data. Field number 16 in the Station Description Record, "Classification System for Vehicle 

Classification," determines the number of classes expected from the station. The default 

classification system is the FHWA 13 class system (see Appendix 4-C). 

These counts should be checked for reasonableness. For example, Class 13 should not be larger 

than 99. VTRIS allows users to set a limit for each class count 

11. Class 1 Count (Columns 25-29) - Optional 

Class 1 is for Motorcycles, which is an optional class. If motorcycles are not counted, enter "-1" or 

blanks in the Class 1 field. 

12. Class 2 Count (Columns 30-34) - Critical

Class 2 is for Passenger Cars. 

13. Class 3 Count (Columns 35-39) - Optional

Class 3 is for Other Two-Axle, Four-Tire, Single-Unit Vehicles. However, classes 2 and 3 may be 

combined, in which case the total for both classes should be entered in the class 2 field and "-1" or 

blanks in the Class 3 field. 

14. Class 4 Count (Columns 40-44) - Critical

Class 4 is for Buses. 

15. Class 5 Count (Columns 45-49) - Critical

Class 5 is for Two-Axle, Six-Tire, Single-Unit Trucks. 

16. Class 6 Count (Columns 50-54) - Critical

Class 6 is for Three-Axle, Single-Unit Trucks. 

17. Class 7 Count (Columns 55-59) - Critical

Class 7 is for Four-or-More Axle, Single-Unit Trucks. 

18. Class 8 Count (Columns 60-64) - Critical

Class 8 is for Four-or-Less Axle, Single-Trailer Trucks. 
19. Class 9 Count (Columns 65-69) - Critical

Class 9 is for Five-Axle, Single-Trailer Trucks. 

20. Class 10 Count (Columns 70-74) - Critical

Class 10 is for Six-or-More Axle, Single-Trailer Trucks. 

21. Class 11 Count (Columns 75-79) - Critical

Class 11 is for Five-or-Less Axle, Multi-Trailer Trucks. 

22. Class 12 Count (Columns 80-84) - Critical

Class 12 is for Six-Axle, Multi-Trailer Trucks. 

23. Class 13 Count (Columns 85-89) - Critical

Class 13 is for Seven-or-More Axle, Multi-Trailer Trucks. 

The Vehicle Classification record may be ended here if exactly 13 classes are used. However, some 

automatic vehicle classification systems have one or two more classes usually designating 

"Unclassified" or "Unclassifiable" vehicles. If Class 14 and/or Class 15 are included such that the 

total of all the classes equals the total volume, then the Total Volume field may be left blank.

24. Class 14 Count (Columns 90-94) - Optional

If a Class 14 is used, enter the count for the hour here. 

25. Class 15 Count (Columns 95-99) - Optional 

If a Class 15 is used, enter the count for the hour here. 
Table 3: Vehicle Classification Record 

(OMB No. 2125-0587 Expiration 4/30/2004)

 Field Columns Length Description

 1 1 1 Record Type 

 2 2-3 2 FIPS State Code 

 3 4-9 6 Station ID 

 4 10 1 Direction of Travel Code 

 5 11 1 Lane of Travel 

 6 12-13 2 Year of Data 

 7 14-15 2 Month of Data 

 8 16-17 2 Day of Data 

 9 18-19 2 Hour of Data 

 10 20-24 5 Total Volume 

 11 25-29 5 Class 1 Count 

 12 30-34 5 Class 2 Count 

 13 35-39 5 Class 3 Count 

 14 40-44 5 Class 4 Count 

 15 45-49 5 Class 5 Count 

 16 50-54 5 Class 6 Count 

 17 55-59 5 Class 7 Count 

 18 60-64 5 Class 8 Count 

 19 65-69 5 Class 9 Count 

 20 70-74 5 Class 10 Count 

 21 75-79 5 Class 11 Count 

 22 80-84 5 Class 12 Count 

 23 85-89 5 Class 13 Count 

 End the record here if the FHWA 13 class system is being used. 

 24 90-94 5 Class 14 Count (optional) 

 25 95-99 5 Class 15 Count (optional) 
CHAPTER 5 

TRUCK WEIGHT DATA FORMATS 

The Truck Weight file contains one record for each truck with its axle weights and spacings. 

The optional file naming convention is "ssyy.WGT", where ss is the state postal abbreviation and yy 

is the last two digits of the year. Table 4 summarizes the Truck Weight record. 

Fields designated as Critical are required for entry into the HVTIS database. 

1. Record Type (Column 1) - Critical

W = Truck weight record 

2. FIPS State Code (Columns 2-3) - Critical - See chapter 2. 

3. Station Identification (Columns 4-9) - Critical - See chapter 2. 

4. Direction of Travel Code (Column 10) - Critical - See chapter 2. 

5. Lane of Travel (Column 11) - Critical - See chapter 2. 

Note: The Station ID, Direction of Travel, and Lane of Travel make up the Station Code. 

There should be one Station Description record per Station Code. 

6. Year of Data (Columns 12-13) - Critical - See chapter 2. 

7. Month of Data (Columns 14-15) - Critical - See chapter 3. 

8. Day of Data (Columns 16-17) - Critical - See chapter 3. 

9. Hour of Data (Columns 18-19) - Critical

Code the beginning of the hour in which the count was taken: 

 00 = 0:01 a.m. to 1:00 a.m. 

 01 = 1:01 a.m. to 2:00 a.m. 

 . 

 . 

 . 

 22 = 10:01 p.m. to 11:00 p.m. 

 23 = 11:01 p.m. to Midnight 

10. Vehicle Class (Columns 20-21) - Critical

Enter the class of the vehicle from FHWA Vehicle Classes 1 to 13. Classes 1 - 3 are ordinarily 

omitted. 
A dummy vehicle class of -1 indicates that weight data for this hour are missing. A dummy vehicle 

class of 0 indicates that weight data for this hour are not missing, and thus if there are no Truck 

Weight records for the hour, then there were no trucks during that hour. Without these indications, 

no Truck Weight records for an hour might be interpreted to mean that the WIM system was not 

working. 

11. Open (Columns 22-24) - Optional

This field is for special studies or State use such as for vehicle speed (kilometers per hour) or 

pavement temperature (degrees Celsius in the range -99 to +99). 

12. Total Weight of Vehicle (Columns 25-28) 

 

Enter the gross vehicle weight to the nearest tenth of a metric ton (100 kilograms) without a decimal 

point. This should equal the sum of all the axle weights except for rounding. 

13. Number of Axles (Columns 29-30) 

Enter the total number of axles in use by the vehicle (including any trailers). 

The Number of Axles determines how many Axle Weight and Spacing fields will be expected. Axle 

Weight and Spacing fields that are not needed may be omitted. If a fixed-length record is desired, 

pad the record with blanks to the desired length.

The rest of the record alternates between axle weights and axle spacings, starting from the front of 

the vehicle. Axle weights are to the nearest tenth of a metric ton (100 kilograms) without a decimal 

point. Axle spacings are to the nearest tenth of a meter (100 millimeters) without a decimal point. 

Reasonableness checks should be performed on the axle weights and spacings. The default limits in 

VTRIS are 200 to 20,000 kilograms for axle weights and 0.5 to 15 meters for axle spacings. The 

user may adjust these values. 

14. A-axle Weight (Columns 31-33) 

15. A-B Axle Spacing (Columns 34-36) 

16. B-axle Weight (Columns 37-39) 

17. B-C Axle Spacing (Columns 40-42) 

18. C-axle Weight (Columns 43-45) 

19. C-D Axle Spacing (Columns 46-48) 

20. D-axle Weight (Columns 49-51) 
21. D-E Axle Spacing (Columns 52-54) 

22. E-axle Weight (Columns 55-57) 

23. E-F Axle Spacing (Columns 58-60) 

24. F-axle Weight (Columns 61-63) 

25. F-G Axle Spacing (Columns 64-66) 

26. G-axle Weight (Columns 67-69) 

27. G-H Axle Spacing (Columns 70-72) 

28. H-axle Weight (Columns 73-75) 

29. H-I Axle Spacing (Columns 76-78) 

30. I-axle Spacing (Columns 79-81) 

31. I-J Axle Spacing (Columns 82-84) 

32. J-axle Weight (Columns 85-87) 

33. J-K Axle Spacing (Columns 88-90) 

34. K-axle Weight (Columns 91-93) 

35. K-L Axle Spacing (Columns 94-96) 

36. L-axle Weight (Columns 97-99) 

37. L-M Axle Spacing (Columns 100-102) 

38. M-axle Weight (Columns 103-105) 

Additional axle spacing and axle weight fields may be added in the same manner if needed. 
Table 4: Truck Weight Record 

(OMB No. 2125-0587 Expiration 4/30/2004)

Field Columns Length Description

 1 1 1 Record Type 

 2 2-3 2 FIPS State Code 

 3 4-9 6 Station ID 

 4 10 1 Direction of Travel Code 

 5 11 1 Lane of Travel 

 6 12-13 2 Year of Data 

 7 14-15 2 Month of Data 

 8 16-17 2 Day of Data 

 9 18-19 2 Hour of Data 

10 20-21 2 Vehicle Class 

11 22-24 3 Open 

12 25-28 4 Total Weight of Vehicle 

13 29-30 2 Number of Axles 

14 31-33 3 A-axle Weight 

15 34-36 3 A-B Axle Spacing 

16 37-39 3 B-axle Weight 

17 40-42 3 B-C Axle Spacing 

18 43-45 3 C-axle Weight 

19 46-48 3 C-D Axle Spacing 

20 49-51 3 D-axle Weight 

21 52-54 3 D-E Axle Spacing 

22 55-57 3 E-axle Weight 

23 58-60 3 E-F Axle Spacing 

24 61-63 3 F-axle Weight 

25 64-66 3 F-G Axle Spacing 

26 67-69 3 G-axle Weight 

27 70-72 3 G-H Axle Spacing 

28 73-75 3 H-axle Weight 

29 76-78 3 H-I Axle Spacing 

30 79-81 3 I-axle Weight 

31 82-84 3 I-J Axle Spacing 

32 85-87 3 J-axle Weight 

33 88-90 3 J-K Axle Spacing 

34 91-93 3 K-axle Weight 

35 94-96 3 K-L Axle Spacing 

36 97-99 3 L-axle Weight 

37 100-102 3 L-M Axle Spacing 

38 103-105 3 M-axle Weight 

Note: The number of axles determines the number of axle weight and spacing fields. 
APPENDIX A 

FHWA VEHICLE TYPES 

The classification scheme is separated into categories depending on whether the vehicle 

carries passengers or commodities. Non-passenger vehicles are further subdivided by number of 

axles and number of units, including both power and trailer units. Note that the addition of a light 

trailer to a vehicle does not change the classification of the vehicle. 

Automatic vehicle classifiers need an algorithm to interpret axle spacing information to 

correctly classify vehicles into these categories. The algorithm most commonly used is based on the 

“Scheme F” developed by Maine DOT in the mid-1980s. The FHWA does not endorse “Scheme 

F” or any other classification algorithm. Axle spacing characteristics for specific vehicle types are 

known to change from State to State. As a result, no single algorithm is best for all cases. It is up to 

each agency to develop, test, and refine an algorithm that meets its own needs. 

FHWA VEHICLE CLASSES WITH DEFINITIONS 

1. Motorcycles (Optional) -- All two or three-wheeled motorized vehicles. Typical vehicles in 

this category have saddle type seats and are steered by handlebars rather than steering 

wheels. This category includes motorcycles, motor scooters, mopeds, motor-powered 

bicycles, and three-wheel motorcycles. This vehicle type may be reported at the 

option of the State. 

2. Passenger Cars -- All sedans, coupes, and station wagons manufactured primarily for the 

purpose of carrying passengers and including those passenger cars pulling 

recreational or other light trailers. 

3. Other Two-Axle, Four-Tire Single Unit Vehicles -- All two-axle, four-tire, vehicles, other 

than passenger cars. Included in this classification are pickups, panels, vans, and 

other vehicles such as campers, motor homes, ambulances, hearses, carryalls, and 

minibuses. Other two-axle, four-tire single-unit vehicles pulling recreational or other 

light trailers are included in this classification. Because automatic vehicle classifiers 

have difficulty distinguishing class 3 from class 2, these two classes may be 

combined into class 2.

4. Buses -- All vehicles manufactured as traditional passenger-carrying buses with two axles 

and six tires or three or more axles. This category includes only traditional buses 

(including school buses) functioning as passenger-carrying vehicles. Modified buses 

should be considered to be a truck and should be appropriately classified. 

NOTE: In reporting information on trucks the following criteria should be used: 
 a. Truck tractor units traveling without a trailer will be considered single-unit trucks. 

 b. A truck tractor unit pulling other such units in a "saddle mount" configuration will be 

considered one single-unit truck and will be defined only by the axles on the pulling 

unit. 

 c. Vehicles are defined by the number of axles in contact with the road. Therefore, 

"floating" axles are counted only when in the down position. 

 d. The term "trailer" includes both semi- and full trailers. 

5. Two-Axle, Six-Tire, Single-Unit Trucks -- All vehicles on a single frame including trucks, 

camping and recreational vehicles, motor homes, etc., with two axles and dual rear 

wheels. 

6. Three-Axle Single-Unit Trucks -- All vehicles on a single frame including trucks, camping 

and recreational vehicles, motor homes, etc., with three axles. 

7. Four or More Axle Single-Unit Trucks -- All trucks on a single frame with four or more 

axles. 

8. Four or Fewer Axle Single-Trailer Trucks -- All vehicles with four or fewer axles 

consisting of two units, one of which is a tractor or straight truck power unit. 

9. Five-Axle Single-Trailer Trucks -- All five-axle vehicles consisting of two units, one of 

which is a tractor or straight truck power unit. 

10. Six or More Axle Single-Trailer Trucks -- All vehicles with six or more axles consisting of 

two units, one of which is a tractor or straight truck power unit. 

11. Five or fewer Axle Multi-Trailer Trucks -- All vehicles with five or fewer axles consisting 

of three or more units, one of which is a tractor or straight truck power unit. 

12. Six-Axle Multi-Trailer Trucks -- All six-axle vehicles consisting of three or more units, one 

of which is a tractor or straight truck power unit. 

13. Seven or More Axle Multi-Trailer Trucks -- All vehicles with seven or more axles 

consisting of three or more units, one of which is a tractor or straight truck power 

unit.