III. a. Make selection based on single query and determining the crash frequency
             Estimated time:
             2 minutes
An equation would help to give the desired output. A query is a small equation which gives the desired output
This exercise will help you:
  • a1. Navigate layer properties
  • a2. View query builder
  • a3. Build a single query
  • a4. Determining the crash frequency


                                                   Start VideoDemo
Text Version:
  • a1: Right click on “All _Crashes_ 04 - 06 Interstates”

  • a1: [Left] Click on “Properties”

  • a2: [Left] Click on “Definition Query” and then “Query Builder”

  • a3: Double Click on “ROUTE” and press =

  • a3: [Left] Click on “ROUTE” and [left] click on “Get Unique Values”

  • a3: Select ‘40’ and double [left] click

  • a3: [Left] click on “Verify”

  • a3: A message stating “The expression was successfully verified” is displayed, [left] click “OK”

  • a3: Press “OK”

  • a3: Press “Apply”

  • a4: Right click on the “All _Crashes_ 04 - 06 Interstates”

  • a4: [Left] Click on “Open Attribute Table” scroll to the end to find all the columns

  • a4: The total frequency of crashes is the number of rows present in the “Attribute Table”

  • a4: Close the “Attribute Table”


DELIVERABLES
State your query and present the results for the following:

D1. Find the frequency of crashes on route 30.