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Description for FARS/MCMIS Matching Tool
The FARS/MCMIS Fatal Crash Record Matching Tool is designed to
help reconcile differences between the Fatality Analysis Reporting System (FARS)
and Motor Carrier Management Information System (MCMIS) databases. A methodology
was developed to "match" fatal large truck and bus crash records between the FARS
and MCMIS databases. The methodology defines a "matched record" between the two
databases as a crash that involved at least one fatality, involved a large truck
or bus, and contains the same information in several key fields (e.g., county, date,
time, VIN, DOT #, etc.). The methodology has more than 40 unique matching combinations
that can produce a single match between FARS and MCMIS fatal crash records.
The FARS record set also contains records from the FARS' Parkwork data set, which includes
information about parked and working vehicles involved in fatal crashes. A "parked vehicle"
is defined as a motor vehicle that was stopped off of the roadway when it became involved in
a fatal crash. A "working vehicle" is defined as a motor vehicle that was in the act of performing
highway construction, maintenance, or utility work related to the traffic way when it became
involved in a fatal crash.
What should I do
with the matching results (the "matching tool")?
How is this Analysis
Different from the State Safety Data Quality (SSDQ) evaluation?
Is the Tool Expected
to Match all Fatal Crash Records Between FARS and MCMIS?
How does the Matching
Tool determine a "matched record set"?
Descriptions of FARS and MCMIS Vehicle Body Types.
How are parked
and working vehicles defined?
What should I do with the matching results (the "matching tool")?
Review the results of the
Matching Tool to determine if all reportable
fatal crash records have been reported to MCMIS from your State database.
- Step 1: Review the Records Matched- One FARS crash record is matched to one
MCMIS fatal crash record. Only large truck and bus vehicle types were included in
this set of results.
- Step 2: Review the Records Potentially Matched- The records that were not
definitely matched by the matching algorithm were evaluated as potential matches
against non-truck and bus vehicle types in FARS (e.g., automobile, light truck)
and MCMIS non-fatal crash records. Potentially matched record sets are identified
in two lists: FARS truck and bus records potentially matched to MCMIS non-fatal
crash records, and FARS non-truck and bus records potentially matched to MCMIS fatal
crash records.
- Determine why a fatal record(s) reported to FARS as a large truck or bus was reported
to MCMIS as a non-fatal crash record.
- Determine why a fatal record(s) reported to MCMIS as a large truck or bus was reported
to FARS as non-truck or bus vehicle type (e.g., automobile, light truck).
- If crash records were categorized incorrectly in MCMIS, update crash records accordingly
and upload to MCMIS. If crash records were categorized incorrectly in FARS, contact
your State's FARS analyst.
- Step 3: Review the Records Not Matched- The FARS and MCMIS fatal crash records
that were evaluated by the matching algorithm but could not be potentially matched
are identified in two separate lists: FARS Truck and Bus records, and MCMIS fatal
crash records.
- Review these record sets for missing data. A match requires several key fields to
be the same in both the FARS and MCMIS records. Missing data or typographical errors
can be identified and corrected, and then records can be re-uploaded to the appropriate
data source to enable a definitive match.
- Identify if there are fatal crash records in MCMIS that should have been categorized
as non-fatal. This may be true for some States where their MCMIS fatal crash count
is higher than the FARS fatal crash count.
- A definitive match for all fatal records may not be possible because the definitions
of large trucks and buses differ slightly.
- Step 4: Add comments to each record (or pair of records) following the review of
the matching results, describing actions to be taken or reasons why records may
not match. Each State should only add comments to their State records. Comments
will be displayed for as long as the record is evaluated.
- Display the comment option by enabling the "Show Comments" selection above.
- Click on the "Add Comment" / "Edit Comment" link at the end of each record to either
add a new comment or edit an existing comment. Click on "Save Comment" when finished.
How is this Analysis Different from the State Safety Data Quality (SSDQ) evaluation?
- The SSDQ evaluation (color-coded map) currently provides a comparison of the total number of MCMIS and FARS fatal crash records
. These crash records are evaluated and the results are shown in the fatal crash
completeness measure. The SSDQ evaluation does not "match" records between FARS
and MCMIS.
- The SSDQ fatal crash completeness measure only examines large trucksinvolved
in fatal crashes. The Matching Tool examines large trucks and buses
involved in fatal crashes. This broader analysis allows States to determine if both
vehicle types involved in fatal crashes are being reported to FMCSA.
- The Matching Tool does not assign a rating - good, fair, or poor
- to the matching results. The results of the Matching Tool are not usedin
the SSDQ methodology.
Is the Tool Expected to Match all Fatal Crash Records Between FARS and MCMIS?
- No, it's possible to have differences between the FARS and MCMIS databases. These
databases may have different fatal crash counts due to variances in reportable vehicle
configuration definitions.
How does the Matching Tool determine a "matched record set"?
The tool examines several variables from the FARS and MCMIS data sets. If the key
variables in a record are the same or almost the same in some cases, then the tool
returns a matched record set.
The tool has 54 unique matching combinations that can produce a matched record set.
Each matching combination requires a few variables from each data source to match
exactly to produce a matched record set. The following nine variables are examined
from the FARS and MCMIS data sources to produce a matched record set: county, date,
time, vehicle identification number (VIN), DOT number, MC/MX number, Truck or Bus
indicator, driver age, and driver license state. These matching combinations are
shown in Table 1, and the definitions of each variable are described in Table 2.
The matching combinations rely upon primary and secondary variable types. The primary
variables - nine that are listed above - are evaluated as they were reported to
the FARS and MCMIS. The secondary variables include the month and year data fields
and sub-variables of the original variables. The DOT number and the VIN were created
into sub-variables. For example, the VIN contains 12 alpha-numeric characters from
the FARS data source and 17 alpha-numeric characters from the MCMIS data source.
The sub-variable "VIN10" examines 10 of the original 12 alpha-numeric characters
in the FARS and 17 characters from the MCMIS. The eight sub-variables created for
this tool are described in Table 1. The tool can create a match without using all
characters from the DOT and the VIN. Matching combinations 49, 50, 51, 52, 53, and
54 are applied only for TN, SC, and ND, because significant crash event data are
missing (e.g., US DOT #, MC/MX #, VIN).
Table 2. Descriptions of Primary and Secondary Variables
used in the FARS/MCMIS Matching Methodology |
| Variable | Description |
| County |
County code identifies the location where the crash occurred. |
| Date |
Accident date identifies the exact date in month/day/year of when the crash occurred. |
| Time |
Accident time identifies the exact time in hour and minute of when the crash occurred. |
| VIN |
Vehicle Identifcation Numbers consist of 17 alpha-numeric characters that identify the individual vehicle involved in the crash: FARS only provides up to 12 alpha-numeric chracters and MCMIS provies up to 17 alpha-numeric characters. Therefore, the first 12 characters of the MCMIS 17-chracter VIN is matched with the FARS 12-character VIN. For example, a MCMIS 17-character VIN could be 1HTSCABM1TH200416 and a FAR 12-character VIN could 1HTSCABM1TH2. |
| DOT |
US DOT Number. FARS provides 9-digit DOT and MCMIS provides 7-digit DOT. For example, FARS DOT is 103245860 and MCMIS DOT is 1032458. |
| MC/MX# |
Motor carrier numbers that are issued as carriers are registered. |
| TB |
Truck or Bus indicator. |
| Driver Age |
Age of Driver. |
| Driver License State |
State that issued the driver's license. |
| VIN10 |
The sub-VIN 10 alpha-numeric characters within the actual VIN. The last, first, or middle ten characters within the VIN are used. For example, (1)FARS WIN could be 1HTMHZPM2MH2 and MCMIS VIN could be 1NTMHZPM2MH295359; (2) FARS VIN could be 1FUPACXB0PL4 and MCMIS VIN could be FUPACXB0OL474360; or (3) FARS VIN could be 1GS9C421BV58 and MCMIS VIN could be 1Gs9C321BV5582717. In the last example, the VIN could be matched by the first digit, but in some cases, there might be a typo in number "1" which is entered as a capitalized leter "|". |
| VIN8 |
The sub-VIN with eight alpha-numeric characters within the actual VIN. For example, (1) FARS VIN could be 1GS9C421BV58 and MCMIS could be 1GS9C4218V5582717; or (2) FARS VIN could be 1FUJBBCG14LN and MCMIS VIN could be 1FUTBBCG14LN21387. |
| VIN7 |
The sub-VIN with seven alpha-numeric characters within the actual VIN. For example, (1) FARS VIN could be 1XKWD69XX1R8 and MCMIS could be 1XKW69XX1R863875; or (2) FARS could be 1FUJA6CV76LU and MCMIS VIN could be 1FUYJA6CV76LU3131. |
| VIN6 |
The sub-VIN with six alpha-numeric characters within the actual VIN. For example, FARS VIN could be 1M2AA13Y4RW0 and MCMIS VIN could be 1M214A1344RW03664. |
| VIN5 |
The sub-VIN with five alpha-numeric characters within the actual VIN. For example, (1) FARS VIN could be 1FUJBBBG53PG and MCMIS VIN could be 1FUJBBG53PG991055; (2) FARS VIN could be 4V1WDBJH4SN6 and MCMIS VIN could be 4V1W0BJH4SN689529; or (3) FARS VIN could be 1FUJBBCGX5LU and MCMIS VIN could be 1FUJBBVGX5LU37716. |
| VIN4 |
The sub-VIN with four alpha-numeric characters within the actual VIN. For example, FARS VIN could be 1GBJ7H1CXYJ5 and MCMIS VIN could be 1GBJ2H1CX4J522197. |
| VIN3 |
The sub-VIN with three alpha-numeric characters within the actual VIN. For example, FARS VIN could be 1FUYSSZB6XLA and MCMIS VIN could be 1FUY5SZB8XLA10131. |
Descriptions of FARS and MCMIS Vehicle Body Types.
-
Each record in both FARS and MCMIS are labeled with its vehicle type. The descriptions
for each vehicle type for each data source are described as follows:
FARS body types:
-
Truck - a vehicle having a gross vehicle weight rating (GVWR) of more than 10,000
pounds.
Bus - a large motor vehicle used to carry more than 10 passengers, including school
buses, inter-city buses and transit buses.
Automobile - convertibles, 2-5 door sedans, auto-based pickups, station wagons,
large limousines (more than 4 side doors or stretch), 3-wheel autos or derivatives.
Utility Vehicle - a transport vehicle designed for carrying persons and generally
considered a multi-purpose vehicle that is designed to have off-road capabilities.
These vehicles are generally 4-wheel-drive and have increased ground clearance.
A utility vehicle typically has a gross vehicle weight rating of 10,000 pounds or
less.
Van - van-based light trucks that include minivans, large vans, step vans, other
and unknown van types.
Light Truck - light conventional trucks with a gross vehicle weight rating of 10,000
pounds or less, including compact pickups, standard pickups, convertible pickups
and unknown light conventional truck types.
Motor Home - van-based or pickup-based motor homes, medium/heavy truck -based motor
homes, and campers or motor homes w/ unknown truck types.
Motorcycle - motorcycles, mopeds, 3-wheel motorcycles or mopeds, off-road motorcycles
(2-wheel), other motored cycle types (includes mini-bikes, motor scooters, and pocket
motorcycles), unknown motored cycle types, and all-terrain vehicles (3 or 4 wheels).
Other - Other vehicles that include snowmobiles, farm equipment other than trucks,
construction equipment other than trucks, other vehicle types (such as go-carts,
fork-lifts, city street sweepers, dune/swamp buggies and golf carts), and unknown
body types.
MCMIS body types:
-
Truck - a vehicle designed, used, or maintained primarily for carrying property,
with a gross vehicle weight rating (GVWR) of more than 10,000 pounds or a gross
combination weight rating (GCWR) over 10,000 pounds.
Bus - A motor vehicle with seats for at least nine (9) people, including the driver's
seat.
How are parked and working vehicles defined?
- FARS defines a parked vehicle as a motor vehicle that is stopped off the roadway,
while a working vehicle is a motor vehicle that was in the act of performing highway
construction, maintenance, or utility work related to the traffic way when it became
an involved in the crash.