Required and recommended fields for Intersection Magic
Intersection Magic has many capabilities, and depending on your use of the program, you may choose to include a variety of fields for analysis. Engineers, police, planners all have different needs. In addition, Intersection Magic requires a number of fields regardless of your specific analysis needs.
Intersection Magic has several pre-defined fields: Case id; Primary andCross Streets; Mile markers and Address locations;Distance from intersection; Date; and Time. These are referred to as “Base fields“. The valid ranges for these fields is given in the lists below.
In addition, 40 user-defined fields may also be stored. These are numeric fields with a valid range of 0 to 254. If an existing collision database stores its data as text fields, a conversion to numbers will be necessary. Provisions for this conversion exist in IMW. In this case, a table is created for each field describing how to convert text to numbers. During program execution, the user will still see and use text values for all functions. The numbers are just for internal program use.
Free-form text is generally not useful to the program. For example, if data entry operators include values like “rr end; rear end; rear; r end;” it will be a challenge to prepare a working configuration. This is especially true for location information.Required Fields:
- Unique Case Id Number: (up to 14 alpha-numeric characters)
- Date (in a standard format such as mm/dd/[cc]yy, ccyymmdd, etc )
- Location of crash (at least one of the following – all three can be used simultanously):
- Primary and nearest cross street names (up to 29 characters for each street) This is the most common means of identifying locations in urban and rural city settings.
- Intersection node number: Must be a numeric value containing no spaces or alpha characters. An (optional) lookup table may also be provided.
- Route and Mile marker: Usually used in county or state DOT agencies
- Street and hundred block: Usually used in urban settings as a supplement to “Primary and nearest cross street names”.
- Direction of travel for each of the involved vehicles (valid values: 0-255)
- Type of Collision (0-255) It is important that this field indicate rear-end and sideswipe collision types.
- Vehicle movements prior to collision (left turn, slowing, backing, straight, etc. 0-255) This field is needed when rendering a collision diagram to enable the program to render appropriate arrows. (i.e. bent left, bent right, straight, etc.) Without this field, all arrows will be straight.
- Distance & Direction from intersection (Distance 0-64,000; Direction 0-255) This field is used to place crashes in the appropriate positions in the diagram. Without it, many assumptions need to be made about vehicles in or near an intersection.
- Indication of injuries (may be a “severity” field, or simply a “number of injuries” field. Range 0-255) This field is used to render an injury symbol.
- Indication of fatalities (may be a “severity” field, or simply a “number of fatalities” field. Range 0-255) This field is used to render a fatality symbol.
- Indication of a pedestrian, bicycle, or fixed object (0-255) These values are used to render appropriate objects.
- Lighting conditions (0-255) Used to render graphic indication of nightime crashes.
- Driver or DUI conditions (0-255) Used to render graphic indication of DUI, etc.
After identifying and populating the required and recommended fields, there will be plenty of user fields not yet populated. The person performing the analysis is the best person to make decisions about the remaining fields.