National Collision Database Online Tutorial

• Main Features of the NCDB
• Using Contributing Factors

This tutorial demonstrates the main features of the National Collision Database Online application (NCDB). We will build two different tables that demonstrate the various features of the application.

Main Features of the NCDB

Part 1: Creating a table

This part of the tutorial shows you how to create a table using the NCDB Online four-part wizard.

• To begin the application, select Start NCDB Online.

Selecting variables

Step one of the wizard, the Select variables page, shows the list of variables that you can use in your analysis. Variables will appear as dimensions in the table that is created.

• You can select up to eight variables. Measures and the variable Year are required, and are already selected.
• Note that the combination of variables you choose could result in a table that is too large to build. In that case you will have to select fewer variables, or variables with fewer items.

There are two different reasons why you might select a particular variable:

• To filter the results to a single value (for example, if you’re only interested in fatal collisions).
• To compare the results between multiple different values (for example, which driver age range has the highest frequency of fatalities?).

For this tutorial we are interested in a broad view of the collisions that occurred in 2006. Measures and Year are already pre-selected. We will add Collision Sev (Collision severity).

To select a variable:

• Select Collision Sev from the list of variables, and then select Step 2: Select items at the top of the page.

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Selecting items

Step two of the wizard, the Select items page, allows you to select measures and the items for each of your variables.

To select items:

1. First select the name of a variable on the left, under Variables. We will select Year.
2. Remove the totals by deselecting everything under Totals to calculate. (Because there is only going to be one year in our table, 2006, there is no need for totals in the Year variable.)
3. Because we have disabled totals for this variable, it does not matter what is selected under Display of totals and items.
4. Under Items, select Clear all and then select 2006.
5. For Measures and Collison Sev, we will accept the defaults. It is not necessary to open variables in order to accept the defaults.
6. When you have finished making your item selections, select Step 3: Set table layout.

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Setting the table layout

Step three of the wizard, the Set table layout page, allows you to design your table by placing each dimension on the rows, on the columns, or in the Other dimension area.

By default our table has the following characteristics:

• Collision Sev is on the rows.
• Year and Measures are on the columns. Year has position 1 and Measures has position 2, which means that Measures will be nested inside Year.
• The size of the page is set to 50 rows by 8 columns.

For now we will accept the defaults. You can return to this screen any time if you want to change the layout of your table.

Select Step 4: View table to continue.

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Viewing the table

Step four of the wizard shows the table which has been created. It has the following characteristics:

• The table's title is Measures by Year by Collision Sev.
• Underneath the title is the Download area. Five download formats are provided:
  • IVT
  • XLS
  • CSV
  • SSV
  • PDF
• Year and Measures are on the columns of the table, with Measures nested inside Year. Collision Severity is on the rows.
• Year shows one year, 2006.
• Measures has the following five items:
  • Number of collisions
  • Number of vehicles
  • Number of persons
  • Number of injured
  • Number of fatalities
• Collision Sev has the following three items:
  • Total
  • Fatal collision
  • Injury collision

By consulting the Fatal collision row, for example, we are able to learn that in 2006 there were 2599 fatal collisions involving 4305 vehicles and 6906 persons, of whom 2350 were injured and 2884 were killed.

This concludes Part 1 of the tutorial.

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Part 2: Reorganizing the table

This part of the tutorial shows you how to do the following:

• Add another year to the table
• Increase the display of columns from 8 to 10
• Download the table as a PDF file

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Adding another year to the table

Now we will add the year 2007 to the table. This will give us the ability to compare data for the two years 2006 and 2007.

To add another year to the table:

1. Select Step 2: Select items.
2. Select Year in the list on the left to open it. Select 2007, leaving 2006 selected. Leave all the options unchecked under Totals to calculate.
3. Select Step 4: View table.

The updated table appears in the table viewer. Now the Year dimension on the columns has two years, 2006 and 2007.

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Repaginating the table

Now our table has two years on the columns, but we can tell from the Pagination areas at the top and bottom of the table that only columns 1 to 8 of 10 are being displayed.

To repaginate the table:

1. Select Step 3: Set table layout.
2. Under Page size, change Set display columns to 10.
3. Select Step 4: View table.

Now our table displays all three rows and all ten columns.

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Downloading the table

Now that we have our table arranged the way we like it, we will download it to our local computer in PDF format.

Note: in order to maintain acceptable performance on the site, a download limit (the total number of cells that can be downloaded) has been set. If you exceed this limit a message will appear. In that case you should reduce the number of variables in your table or the number of selected items in the variables.

To download a table to PDF:

• In the Download area underneath the table's title, select the link for PDF.

You will be shown a Download dialog that tells you the size of the file. To proceed, select Download.

• To return to the View table page, select Back.

This concludes Part 2 of the tutorials.

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Part 3: Starting a new table

This part of the tutorial shows you how to do the following:

• Start a new table
• Change the dimension order
• Change the item selections

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Starting a new table

For the third part of this tutorial, we will generate a new table based on vehicle level information. We will look at a cross between month and vehicle type for the year 2008.

For the analysis that we are doing we will select the number of vehicles and the number of fatalities. For now we are not looking at non-fatal injuries. (It is important to note that the fatalities being counted are those in the selected vehicle. The collision may be a fatal collision, but there may be no fatalities associated with the selected vehicle type.)

Note that if you have not downloaded the first table to your local computer, it will be lost when you start a new one. To download a table, select one of the Download links on the Step 4: View table page. See Downloading the table.

To start a new table:

1. Select Step 1: Select variables.
   • On the Select variables page, select Clear all to reset the previous selections. Then select Month and Vehicle type.
2. Select Step 2: Select items.
   • On the Select items page, select Measures and then deselect Number of injured.
   • Select Year. Select Clear all, and then select 2008. Clear all the selections under Totals to calculate.
3. We will accept the default item selections for the other variables. To see the table, select Step 4: View table.

The table appears on the View table page.

• This table has Year and Measures on the columns. Measures is nested inside Year.
• Month and Vehicle type are on the rows. Vehicle type is nested inside Month.

Next we will reorganize the table to make it more useful.

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Changing the dimension order

Our table has Year and Measures on the columns, and Month and Vehicle type on the rows. We will need to organize this table a little differently to get the information of interest. We want to move Year and Measures out of the table and get the months onto the columns.

To change the dimension order:

1. Select Step 3: Set table layout.
2. In Set dimension order, move Year and Measures to the Other area. Then move Month to the columns.
3. In Page size, change the number of display columns to 14.
4. Select Step 4: View table.

The updated table appears on the View table page.

• Year and Measures have been moved out of the body of the table and placed in the Other dimension area at the top.
• Measures has Next and Previous arrows so you can cycle through the measures.
• Month is on the columns. The table has 14 columns now, which is enough to show all 12 months as well as columns for 'Total' and 'Unknown'.
• Vehicle type is on the rows. It has many items for various vehicle types.

Next we will change some of the item selections.

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Changing the item selections

Our table shows some expected patterns. For example, the number of snowmobiles and school buses involved in collisions is low during the summer months, while the number of bicycles involved in collisions is lower during the winter months.

Now we will focus our analysis by reducing the number of vehicle types. Let's say we are only interested in recreational vehicles.

To change the item selections:

1. Select Step 2: Select items.
2. Open Vehicle type and select Clear all to clear all the selections. Then select only the vehicle types that represent recreational vehicles:
   • Motorcycle and moped
   • Off-road vehicle
   • Bicycle
   • Snowmobile
3. Select Step 4: View table.

   The table appears with the vehicle types confined to recreational vehicles.

   Note that even though we have gone back to an earlier step in the wizard and changed our item selections, the layout of the table remains the same, with Year and Measures in the Other dimension area.

This concludes Part 3 of the tutorials.

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Using Contributing Factors

Transport Canada’s National Collision Database contains four data elements (contributing factor 1, contributing factor 2, contributing factor 3, and contributing factor 4) that describe factors from each vehicle that contributed to the collision. Contributing factors are a “vehicle-level” element, meaning that these factors are linked to specific vehicles in the collisions, thus different vehicles within the same collision may have different contributing factors. Contributing factors fall into 4 major categories, including: Driver/Pedestrian Condition, Driver Action, Vehicular Contributing Factors, and Environmental Contributing Factor. It is possible for a vehicle to have multiple contributing factors from the same major category. Data on contributing factors are collected on a per-vehicle basis, and each vehicle may have anywhere from 0 to 4 contributing factors attached to it in a collision.

Using Transport Canada’s NCDB Online tool, the user is able to view data regarding the factors that have contributed to motor vehicle collisions.

Step 1: Selecting Variables

In step 1 of the NCDB online tool the user will be prompted to select which variables they would like to include in the search query. Section E and Section F both contain the Contributing Factors variables. Section E’s Contributing Factors are presented at the collision level, meaning that selecting a contributing factor in this section will present the user with all collisions that had at least 1 vehicle in the collision with the specific factor. Section F’s Contributing Factors are presented at the vehicle level, meaning that selecting a contributing factor in this section will present the user with all vehicles that had the specific factor present.

There are 4 additional sections (Collision Date, Collision Details, Vehicle Details, and Personal Details) from which variables can be selected to specify the query.

In this example, we have selected “Alcohol_V – Under the Influence of Alcohol” and “Drugs_V – Under the Influence of Drugs”, both from section F.

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Step 2: Select Items

In step 2 of the NCDB online tool, the user is able to select the measures as well as the items from the variables previously selected in step 1.

Inside the “Measures” section, the user can select and de-select which measures they want to include in their query.

In our example, the user is able to select the number of vehicles, injuries and fatalities from vehicles that had either alcohol or drugs as a contributing factor in a collision.

For each of the variables the user selected, the user is able to select “Totals to calculate”, “Display of totals and items”, and “Items”. These categories allow the user to select what categories will be displayed in the final table.

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Step 3: Set Table Layout

In step 3 of the NCDB online tool, the user is able to specify the desired dimensions, areas, positions, and page size.

Inside the “Set Dimension Order” section, the “Area” component allows the user to select whether they would like specific variables or measures to appear as columns or rows. The “Position” component allows the user to specify the order in which the variables or measures appear.

Inside the “Page Size” section, the user is able to set the number of rows and columns that they want displayed per page.

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Step 4: View Table

In step 4 of the NCDB Online Tool, the user is able to view the final table displayed according to all of the options that selected in the previous steps. The user is also able to download the table in 5 different file types (IVT, XLS, CSV, SSV, and PDF).

Using our example, the final table shows totals related to alcohol and drugs as contributing factors in collisions. The table displays whether 1, 2, or none of the factors were present in a collision, as well as other valuable information such as the number of vehicles and casualties involved.

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© Her Majesty the Queen in Right of Canada, as represented by the Minister of Transport.