If you want to download a Microsoft Word version of the codebook, please click here. The SWITRS codebook provides a complete description of all the fields including the variable name and all possible values for the field. You must keep in mind that the PARTY and CRASH variable will repeat for as many victims as there are. While considering PARTY or CRASH variables. In the figure, the CRASH variables and the PARTY variables are joined to the VICTIM table.ĭoing so provides a victim-level table that can be summarized (for example, count or sums can be generated), Values from corresponding PARTY and CRASH tables. Injured parties will appear in the VICTIM table uninjured parties will not.Ī common way to work with data of this structure is to create a PARTY table or a VICTIM table that has data from all its parents joined to each row.įor example, if you plan to do analyses at the victim-level, you can start with a VICTIM table and join in Tables is that some parties (i.e., drivers, bicyclists, pedestrians) will also appear in the VICTIM table. The PARTY - VICTIM relationship tells us that the linkage require two variables,ĬASE ID and PARTY NUMBER and that any number of victims can be associated with a party.Īn important aspect of the relationship between the PARTY and VICTIM Variable and any number of PARTY records can be associated with a crash. In the CRASH - PARTY relationship, the records are linked with the CASE ID The rectangles represent data tables the arrows and accompanying text describe the relationship. It is important to understand the relationships when merging tables. The relationships between each pair of tables are represented below. VICTIM has 7 variables: CASE ID, PARTY NUMBER, VICTIM GENDER, VICTIM AGE, VICTIM ROLE, VICTIM SEATING POSITION, and VICTIM SAFETY EQUIPMENT. PARTY has 4 variables: CASE ID, PARTY NUMBER, PARTY AGE, and VEHICLE MAKER. The database is tiny – it only contains information on 2 crashes. The figure shows an example database with CRASH, PARTY, and VICTIM tables. Likewise, VICTIM is a weak entity, because it depends on PARTY for its existence.
Meps codebook driver#
In other words, a driver cannot be a party in a crash unless the crash exists and is in the crash table. PARTY is a “weak” or “child” entity, because it logically depends on an instance of CRASH. CRASH is a “strong” or “parent” entity because it can exist on its own. In this data model, CRASH, PARTY, and VICTIM are entities that have very specific relationships to each other. Another way to conceptualize the data is to use the entity-relationship model common in relational database management systems. The victims can be thought of as being nested within parties and parties can be thought of as being nested within crashes. Injury severity is included in the VICTIM table. For example, a motorcyclist and his passenger are each a victim. The VICTIM table contains information about the victims - persons associated with each party.The information includes personal descriptors and vehicle descriptors. Parties are the major players in a traffic crash - drivers, pedestrians, bicyclists, and parked vehicles. The PARTY table contains information from all parties involved in the crash, one line per party.The CRASH table contains information on each crash, one line per crash.Working with the relational database structure Review the crash summary data, graphs and tables Select the County/City, Bike/Ped, Severity, and Years Working with the relational database structure.
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