#CHP TRAFFIC MEANING DRIVER#

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.

#CHP TRAFFIC MEANING 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.

Chp traffic meaning