Identify centerline crossing head-on crashes:

• Join "A" records shape file and "B" records dbf file
• Query the joined "B" table to select statewide fix-object crashes

• Link the highlighted records in the "B" table to "A" records file (active "B" file and clicked [crash_key] fields)
• Remove all joins in the "B" table
• Remove all links in the "B" table
• Repeat the procedure for each year (i.e., 1989 through 1998 crash data)
• Merge all new linked "A" files to ho_a89_98.shp file using Geoprocess--only fix-object crashes are contained in the merged file

Merge 1989 through 1998 "B" records:

• Export the highlighted records in "B" tables to new tables (e.g., ho_b89.dbf, ho_b90.dbf, …., ho_b98.dbf)
• Add script append.ave located on g drive
• Compile and run the script
• Save the merged table as ho_b89_98.dbf

Merge 1989 through 1998 "C" records--needed for the [severity] field (e.g., fatal, major, minor, and possible injuries):

• Link the highlighted records in each "B" table to its associated "C" table (active "B" file and clicked [crash_key] fields)
• Export the selected records in "C" tables to new tables (e.g., ho_c89.dbf, ho_c90.dbf, …., ho_c98.dbf) using the append.ave script after compiling and running the script

• Save the merged table as ho_c89_98.dbf

Create a shape file for the identified rural 2-lane paved links

• Dissolve st_road.shp based on [mslink] field attribute and save the new file as st_road_mslink_dissolved.shp
• Join rural_2lane_paved.dbf (this is a dbf file that contains all rural 2lane paved links) and st_road_mslink_dissolved.shp (clicked [mslink] fields)
• Query the joined st_road_mslink_dissolved.shp to select the rural 2lane paved links

• Convert st_road_mslink_dissolved.shp to a new shape file: st_rural_2lane_paved.shp
• Disjoin st_road_mslink_dissolved.shp
• Delete st_road_mslink_dissolved.shp theme

• Join st_rural_2lane_paved.shp and ho_a89_98.shp (clicked [shape] fields)

Select assigned crash records within given boundaries (rural areas within 50 meters) that occurred at non-intersection locations:

• Rename the newly created [distance] field to [distance_j]
• Query the joined ho_a89_98.shp

Calculate dollar loss using the c89_98.dbf table:

• Add a new field: [$value]
• Query for injury severity: [severity] = 1 (fatal)
• Field/Calculate to populate the [$value] field for the highlighted records with 800000
• Repeat the same procedure for [severity] equals to 2 (major), 3 (minor), 4 (possible), and 0 (unknown) using 120000, 8000, 2000, and 0; respectively
• Summarize based on [crash_key] and add sum for [$value]
• Save the summarized table as cost_ho.dbf--this table contains total injury cost for each crash

• Join cost_ho.dbf and ho_a89_98.shp (clicked [crash_key] fields)
• Join table containing [AADT], [IRI], [width], and [year] fields and ho_a89_98.shp (clicked [road_link] fields)
• Convert ho_a89_98.shp to a new shape file: 89_98_ho.shp--the new shape file contains all the required fields for ranking high head-on crash locations

• Open 89_98_ho.shp file
• Summarize based on [road_link] field
• Add averages for [AADT] and [lane_length], and sums for [prop_dmg], and [$value] fields
• Save the new table as rank_ho.dbf

• Query rank_ho.dbf to select the links with more than two head-on crashes

• Export the highlighted records to rank_ho_gt2.dbf file
• Open rank_ ho_gt2.dbf in Excel
• Conduct a ranking according to the Iowa DOT procedure
• Open the ranked rank_ ho_gt2.dbf in Arcview
• Select the top 10 locations: ([final_rank] < 11)
• Export the highlighted records to ten_ho_gt2.dbf
• Join ten_ ho_gt2.dbf and st_rural_2lane_paved.shp (clicked [road_link] fields)
• Select the ten joined records in the st_rural_2lane_paved.shp
• Convert to a new shape file: t_10_ho_gt2.shp to show the top 10 locations on the map
• Link t_10_ ho_gt2.shp and 89_98_ho.shp files to inspect the identified high crash locations