Aggregate accidents by ward
First, you'll explore a completed workbook using a story map and learn about the analytical and visualization capabilities of ArcGIS Insights. Then, you'll create a workbook and start your analysis.
Explore a workbook
With ArcGIS Insights, you can create maps and charts to simultaneously analyze spatial and nonspatial data. By exploring a workbook of the completed analysis for this lesson, you'll learn how maps and charts interact with one another in Insights.
- Open the Cycling collisions in Ottawa, Canada story map.
This story map was created using the ArcGIS Insights workbook that you'll create later in this lesson. It has two tabs, Collisions by ward and Collisions by route type. The first tab includes a map of Ottawa and a chart containing both bars and a line (a combo chart). The map shows the proportion of collisions involving cyclists in each ward. Darker colors indicate wards with a higher proportion of collisions involving cyclists.
The first entry in the map legend is labelled > 0.091 - 0.112.
- Click the first entry in the legend.
The corresponding ward is also selected on the map, while other wards are hidden. The selected ward has the highest proportion of collisions involving cyclists.
- On the map, zoom to the selected ward using your mouse wheel. Point to the ward.
A pop-up appears. It provides the ward's name, Somerset, and its value, 0.1124. This value means that 11.24 percent of collisions in the ward involve cyclists.
- Click the Default extent button to return to the original extent of the data.
- On the legend, click the selected entry to clear the selection.
The chart on this page is called a combo chart because it displays two separate charts (a bar chart and a line chart) on the same card.
- On the chart, point to a bar.
The pop-up displays the ward's name and the number of collisions with cyclists that occurred in the ward.
- Click any bar.
The corresponding ward is also selected on the map.
- Click the bar again to deselect it. Point to a node on the line graph.
The pop-up displays the name of the ward and the total number of collisions in the ward (including collisions that did not involve cyclists). Like clicking the bar, clicking the node changes the selection on the map.
- Click the Collisions by route type tab.
This page displays a map of collisions with cyclists in Somerset ward. It also contains a heat chart and stacked bar chart displaying the number of collisions by year and route type.
The map and stacked bar chart are styled by route type. The highest number of collisions occurred on the Suggested Route type, which is a route where a bicycle lane has been suggested.
- On the legend, click Suggested Route.
Collisions that occurred on a suggested route are selected on the map.
- Click Suggested Route again to clear the selection.
You can also use the charts to make selections on the map by route type or year.
- On the heat chart (the chart under the map), click the cell that corresponds to Bike Lane and 2018.
The collisions that took place on bike lanes in 2018 are displayed on the map.
- Press Ctrl while clicking all route types for 2018 to select them.
The map updates to show all collisions in 2018.
- Click the map to clear the selection.
You've explored a finished workbook and become familiar with the way spatial and nonspatial data is linked in ArcGIS Insights. You also learned a bit about the data and the geography of the area of interest.
Add the data
Next, you'll create your own workbook in ArcGIS Insights. First, you'll download the data required for your analysis. Then, you'll add the data to the workbook.
- Go to the Ottawa_Data.gdb item in ArcGIS Online and click the Download button.
This item is a file geodatabase that contains spatial data layers that can be added to ArcGIS applications.
- Go to the Traffic Collisions by Location 2015-2018 item in ArcGIS Online and click the Download button.
This item is a Microsoft Excel spreadsheet that contains information about traffic collisions in Ottawa between 2015 and 2018. You've downloaded the data you'll need for this lesson.
- Go to ArcGIS Insights and click Sign in. Sign in to your ArcGIS organizational account.
To access Insights in ArcGIS Online, your organization's administrator must grant you a license for it. If you don't have an ArcGIS account or a license for Insights, you can sign up for an ArcGIS free trial.
First, you'll create a dataset using the geodatabase you downloaded.
- On the home page, click the Datasets tab.
If the Datasets tab is not available, it's likely that your account isn't licensed to use ArcGIS Insights.
The Datasets tab lists the datasets available in your organization.
- Click New dataset.
- In the New dataset window, click Browse my computer. Browse to and double-click the Ottawa_Data.gdb zip file that you downloaded.
- In the New dataset window, enter the following parameters:
- For Name, type Ottawa Data.
- For Type, choose File geodatabase.
- For Tags, type Wards, Bike Routes.
- For Summary, type Data for Ottawa wards and routes.
- Click Add.
The Ottawa dataset is added to your Datasets page. Next, you'll add it to a workbook.
- In the list of datasets, click the name of the Ottawa Data dataset you created.
The workbook is created and the Add to page window appears. The Ottawa Data dataset is selected by default. The dataset contains two data layers: Wards and SomersetRoutes. For now, you don't need the SomersetRoutes layer.
- For Selected Data, uncheck SomersetRoutes.
Next, you'll upload the spreadsheet of traffic collisions you downloaded previously.
- Click the Upload file tab.
- Click Browse my computer. Browse to and double-click the Traffic_Collisions_by_Location_2015-2018 spreadsheet.
The spreadsheet is added to the Selected Data section. Now that all of your data is selected, you'll add it to the workbook.
- Click Add.
Two datasets are added to your untitled workbook and a map of Ottawa's wards is created.
Create a map card
You use cards and pages to organize information in a workbook. Each page can contain multiple cards, and each card can contain a map, chart, or table.
Your workbook contains one page and one card. The card includes a map of Ottawa's wards. You won't need this map, so you'll delete it.
- Click the map card to enable it. Click the More button and click the Delete button.
The map card is deleted.
- On the ribbon, click Untitled Workbook to make the workbook name editable. Type Ottawa cycling accidents and press Enter.
Next, you'll create a map of traffic collisions. Your traffic collision data is in the form of a spreadsheet. To add it to a map, you'll need to enable its location.
- In the data pane, point to the traffic collisions table, click Dataset options, and choose Enable Location.
The Enable location pane appears. The default method to enable a location is to use coordinate data in the spreadsheet. Your collisions dataset includes information on the longitude and latitude of each collision, and these fields were chosen by default in the pane. However, the dataset also includes X and Y fields, which contain coordinate information that has been converted to a specific spatial reference. You'll use these fields and set the spatial reference accordingly.
- For X (Longitude), choose X. For Y (Latitude), choose Y.
- For Spatial Reference, click the drop-down menu. Type 2951 in the search box and choose 2951 - NAD 1983 CSRS MTM 9.
Your dataset may have multiple collisions that occurred at the same location, so you'll make sure identical features are not aggregated.
- Check Repeat identical features.
- Click Run.
A location field called Coordinates is added to the dataset.
To view the fields in a dataset, click the arrow next to the dataset name.
- In the data pane, drag the traffic collisions dataset onto the page and drop it on the Map drop zone.
A map card is created. It shows traffic collisions in Ottawa as points.
Next, you'll rename the collisions dataset to give it a shorter name.
- In the data pane, point to the traffic collisions dataset and click the Rename dataset button.
- Type Collisions and press Enter.
The dataset is renamed. Next, you'll explore the dataset's fields to become familiar with the data.
- Click the Collisions arrow to expand its fields.
You already learned about the Coordinates, X, Y, Longitude, and Latitude fields when you enabled location. The TOTAL_COLL field counts all collisions in a specific location for a given year, while the CYCLIST_CO field counts collisions involving cyclists and the PEDESTRIAN field counts collisions involving pedestrians. The CYCLIST_CO and PEDESTRIAN fields are included in the calculation of the TOTAL_COLL field.
For your analysis, CYCLIST_CO is the most important field. You'll use this field a lot, but its current name isn't self-explanatory, so you'll rename it.
- Point to the CYCLIST_CO field and click the Rename Field button. Type Number of cyclists and press Enter.
Before you continue your analysis, you'll also rename the page.
- Under the map card, click Page 1, type Collisions by ward, and press Enter.
- On the ribbon, click the Save button.
Count accidents in each ward
You've created a map card and prepared your data. Next, you'll start your analysis of the traffic accidents. As you learned when you looked at the fields in the Collisions dataset, not all collisions involved cyclists. Using the Number of cyclists field, you'll filter the dataset to only show accidents that involved cyclists.
- If necessary, click the map card to activate the toolbar.
- Click the Card filter button.
The New Filter pane appears.
- For Filter By, choose Number of cyclists.
A histogram appears. A histogram is a type of chart that plots the distribution of data. The bars on the histogram indicate points with the same value for the Number of cyclists field.
The Number of cyclists field contains a count of accidents involving cyclists at each location. For many of these locations, the count is 0, meaning no accident involving a cyclist occurred. You'll change the filter so that only locations with a count of 1 or more are included.
- Click the left node of the histogram, change 0 to 1, and press Enter.
The node's position on the histogram updates.
- Click Apply and close the Card Filters pane.
The map updates to show only collisions that involved cyclists.
A result dataset called Collisions is also added to the data pane. Result datasets have an orange icon in the data pane. Because the result dataset has the same name as the original dataset, you'll rename it.
- Rename the result dataset Collisions with cyclists.
Next, you'll aggregate the number of collisions involving cyclists by city ward. That way, you can compare the number of collisions across different areas of the city.
- In the data pane, drag the Wards dataset onto the map card and drop it on the Spatial aggregation drop zone.
The Spatial Aggregation pane appears. By default, Wards is selected for the Choose area layer parameter, Collisions with cyclists is selected for the Choose layer to summarize parameter, and Count of Collisions with cyclists is selected for the Style By parameter.
These are the parameters you'll use.
- Click Run.
The collisions involving cyclists are aggregated into the city wards. The map updates to show the number of collisions involving cyclists in each ward, with larger point symbols corresponding to more collisions. Additionally, the Spatial Aggregation 1 result dataset is added to the data pane.
The largest symbols are in central Ottawa, where the more urban wards are located. The city of Ottawa covers a large and diverse area, encompassing urban, suburban, and rural regions. It's possible that urban wards have higher numbers of collisions involving cyclists because they have more collisions total. It would be helpful to show the wards with the highest proportion of collisions involving cyclists, instead of the highest total count. You can calculate proportions in your data using a process called normalization.
To normalize the data, you need the total number of collisions and the number of collisions involving cyclists. Your aggregation already has collisions involving cyclists, while the Collisions dataset contains the total number of collisions. You'll add the Collisions dataset to the Spatial Aggregation 1 dataset by running another spatial aggregation.
- Drag the Collisions dataset onto the map and drop it on the Spatial aggregation drop zone.
The Spatial Aggregation pane appears. Its parameters are set so that the Collisions dataset will be aggregated by the areas in the Spatial Aggregation 1 dataset. These areas are the same as the city wards.
- Click Run.
A result dataset called Spatial Aggregation 2 is created.
- In the data pane, collapse Collisions and expand Spatial Aggregation 2.
The last two fields in the Spatial Aggregation 2 dataset are Count of Collisions with cyclists and Count of Collisions. The first field was added when you ran spatial aggregation the first time, and the second was added when you ran it the second time. You'll use these fields to style and normalize your map.
- On the map, click the Count of Collisions arrow.
The Layer options pane appears.
- Click the Options tab.
The Options tab of the Layer options pane contains parameters for styling the layer. You'll style the layer by the number of collisions involving cyclists and divide that number by the total count of collisions to normalize the data. You'll also change the symbol type from size to color, because color is more appropriate for depicting proportional data.
- Change the following parameters:
- For Style by, choose Count of Collisions with cyclists.
- For Symbol type, choose Counts and Amounts (Color).
- Expand Classification. For Classification type, choose Equal Interval.
- For Divide Count of Collisions with cyclists by, choose Count of Collisions.
The changes are applied to the map. Areas with higher proportions of accidents involving cyclists are darker colors.
Even when normalized, the central urban wards have the most accidents involving cyclists.
- Close the Layer options pane.
Now that you've created your map, you'll rename the map card to give it a more descriptive name.
- Click the empty area of your page to deactivate the map card. Click Card 1, type Collisions with cyclists by ward, and press Enter.
Create a combo chart
Next, you'll create a combo chart that shows the total number of collisions as a line chart and the number of collisions involving cyclists as a bar chart. This chart will help you visualize the data in a nonspatial way. In ArcGIS Insights, charts and maps are linked if they use the same data, so you can interact with the chart to affect what is displayed on the map.
- In the data pane, for the Spatial Aggregation 2 dataset, press Ctrl while clicking WARD_EN, Count of Collisions with cyclists, and Count of Collisions.
All three fields are selected.
- Drag the fields onto the empty part of the page next to the map card, point to the Chart drop zone, and drop the fields on Combo Chart.
The chart is created, but due to the small default size of the card, some of the data may be difficult to read.
- Drag the handle on the right side of the combo chart to expand its size until all of the ward names are displayed.
- Click an empty area on the page to deactivate the combo chart card. Click Card 1 and rename the card Collisions by ward.
Next, you'll use your map and chart to determine which ward has the highest proportion of cycling accidents. Your map has one ward with a particularly dark symbol, so you'll point to it to learn more about it.
- Click the map card to activate it and zoom in to the darkest wards in the center of the city. Point to the ward with the darkest color.
The pop-up contains the proportion of collisions that involve cyclists, 0.1124 or about 11 percent. The line indicates that the values of all wards range between about 0.01 to 0.11, which means that this ward has the highest value. The average value is 0.04.
The pop-up doesn't contain the name of the ward, so you'll configure it to show the WARD_EN field, which contains ward names.
- In the data pane, for the Spatial Aggregation 2 dataset, point to the Location field and click the Display field button.
- For Choose Display Field, choose WARD_EN.
- Point to the same ward.
The pop-up now shows the ward's name, Somerset. You can compare what you see on the map to the combo chart. On the chart, Somerset ward has both the highest total number of collisions (the line) and the highest number of collisions involving cyclists (the column).
Based on the chart, it appears that the total number of collisions and the number of collisions involving cyclists are the same. However, the line chart and the column chart use a different scale. The scale for count of collisions with cyclists is on the left side of the chart, while the scale for the count of collisions is on the right side. The scale for the latter is 10 times larger.
Outside of Somerset ward, there seems to be a general pattern that wards with more total collisions also have more collisions involving cyclists. One exception is College ward, which has one of the highest numbers of total collisions, but a relatively low number of collisions involving cyclists.
- Save the workbook.
You've created a workbook in ArcGIS Insights, mapped and charted collisions involving cyclists in the city of Ottawa, and examined your results. Next, you'll focus on Somerset ward and take a closer look at the types of streets where the collisions are happening.
Analyze accidents by route type
You know where in Ottawa the most collisions involving cyclists are occurring. But are there any patterns in the routes where collisions occur? If collisions tend to happen on specific roads, it may help city officials identify the best places to add bike routes or other bicycle safety measures.
Create a page
You're entering a new phase of your analysis of bicycling accidents in Ottawa. To keep this phase separate from your previous analysis, you'll create a page in your workbook, add the necessary data, and create maps. First, you'll need the Wards dataset.
- If necessary, open your Ottawa cycling accidents workbook in ArcGIS Insights.
- Drag the Wards dataset from the data pane to the New page drop zone.
A page is created with the Wards dataset in the data pane.
- Click the Collisions by ward tab to return to the first page.
- Drag the Collisions dataset from the data pane to the Page 2 tab.
Because you plan to analyze the collisions based on the routes where they occur, you'll also add a dataset with the city's cycling network. You downloaded this data at the beginning of the lesson but did not add it to the first page of your analysis.
- On the ribbon, click the Add button.
The Add to page window appears.
- Click the Ottawa Data dataset you created previously. (If necessary, search for it.)
- For Selected Data, uncheck Wards.
Now, only SomersetRoutes will be added.
- Click Add.
The dataset is added to the data pane. Additionally, a map card is created showing the routes. You won't need this map, so you'll delete it.
- On the map, click the More button and click the Delete button.
Filter the data
You want to focus your analysis on Somerset ward and on collisions involving cyclists. Although you filtered the Collisions dataset on the previous page, you copied the full, unfiltered dataset to the second page. You'll create two maps, one for collisions and one for wards, to filter the data. You already enabled location for the Collisions layer, so you don't need to do so again.
- Drag the Collisions dataset onto the page and drop it on the Map drop zone. Drag the Wards dataset onto the empty part of the page and drop it on the map drop zone.
Next, you'll filter the Collisions dataset to show only collisions involving cyclists. Previously, you applied this filter to the map card, rather than the dataset. A card filter only affects the card and creates a filtered dataset while the original, unfiltered dataset is still available for use in your analysis. When you apply a filter to a dataset, no new dataset is created. All cards that use the filtered dataset change to include the filter.
Previously, you used both the filtered and unfiltered dataset to normalize the data, so creating a card filter was ideal. You won't use the unfiltered dataset in this part of the analysis, so you'll use a dataset filter.
- In the data pane, expand the Collisions dataset. Point to the Number of cyclists field and click the Dataset filter button.
- In the Filter by Number of cyclists pane, change the left node of the histogram from 0 to 1. Click Apply.
The map of collisions updates to show only the collisions that involved cyclists. Next, you'll filter the collisions again to show only collisions that involved cyclists in Somerset ward. You'll use a card filter to create a new dataset.
- Click the map card showing wards to activate it. Zoom to Somerset ward and click it to select it.
- Drag the selected ward to the map of collisions and drop it on the Filter by selected feature drop zone.
The Spatial Filter pane appears. Its parameters are already set to filter the Collisions layer using the Wards layer. The default parameter for Choose type of filter is Intersects, which means that only collisions that intersect the wards are shown.
If only some features in a dataset are selected, the filter is run using only the selected features. You've selected Somerset ward in the Wards layer, so the filter shows only collisions that occurred in that ward.
- Click Run.
The filter is applied on the map card.
Additionally, a new dataset was added to the data pane.
- In the data pane, change the Spatial Filter 1 name to Somerset collisions.
You've filtered the data for use in your analysis. You no longer need the two map cards you created for filtering.
- Delete the two map cards so that there are no cards remaining on your page.
Join routes and collisions
To analyze cycling collisions by route type, you'll combine the collision data and cycling network data into one dataset. You can combine two datasets using a process called a spatial join.
- On the ribbon, click the Create Relationships button.
The Create Relationships window appears. First, you'll choose the datasets with which to create a relationship.
- In the Create Relationships window, click Somerset collisions and SomersetRoutes.
The datasets are added to the window. Joins must be made based on shared attributes in the two datasets. For your data, location fields were selected as the joining fields, meaning features in the same location will be joined.
By default, ArcGIS Insights performs inner joins, which means that only features that match for both datasets are included in the joined dataset. If any collisions did not occur on bike routes, they are removed. You want to keep all collisions, regardless of whether they intersect the cycling network, so you'll change the join type.
- Between the two datasets, click the edit button.
The Edit Relationship window appears. You can choose to keep all data from both datasets, all data from the left dataset, or all data from the right dataset. The collisions dataset is the left dataset in the join, so you'll choose it.
If you added the routes dataset first, so that Somerset collisions is on the right side of the join, choose Right as the join type instead.
- In the Edit Relationship window, for Choose Relationship Type, choose Left.
- Close the Edit Relationship window. Click Finish.
The joined dataset is added to the data pane.
- In the data pane, collapse the Collisions dataset and expand the Somerset collisions - SomersetRoutes dataset.
The fields in the joined dataset include the fields from the Collisions dataset and the SomersetRoutes dataset. The EXISTING_C field contains descriptions of the types of bike routes.
- Change the name of the EXISTING_C field to Route type.
Next, you'll create a map based on route type using the joined dataset.
- Press Ctrl and select the Coordinates field and the Route type field. Drag the fields onto the page and drop them on the Map drop zone.
A new map card is created.
The color of each collision corresponds to the type of route on which the collision occurred. However, some collisions occurred at the intersection of two different types of routes. You'll change the symbol for these collisions.
- On the map card, click the Route type arrow. In the Layer options pane, click the Options tab.
- For Symbol type, choose Pies.
The symbols on the map change to pie charts. Most symbols have only one color, but collisions that took place at the intersection of two route types have two colors. However, the symbols are large and overlapping, so you'll change the size.
- Click the Style tab. For Size (min - max), change the minimum size to 8 px and the maximum size to 10 px.
Without a legend, the symbols on the map aren't particularly meaningful. You'll add a legend card to the page.
- Click the Legend tab. Click the Pop out legend button.
A legend card is added to the page.
- Move the legend below the map.
- If necesary, close the Layer options pane.
Next, you'll create a heat chart that shows collisions by route type and year.
- In the data pane, for Somerset collisions - SomersetRoutes, select the Year and Route type fields.
- Drag the fields onto the page next to the map card, point to the Chart drop zone, and drop them on the Heat Chart drop zone.
- Drag the heat chart's right handle to expand the chart's size.
Lastly, you'll rename the cards and page.
- Click the empty space on the page to deactivate the cards. Rename the map card Collisions with cyclists in Somerset ward and rename the heat chart Collisions by route type and year.
- Change the name of Page 2 to Collisions by route type.
- Save the workbook.
Interpret the results
Now that you've finished your analysis, you'll interpret the results and draw conclusions from the data. The legend lists five route types:
- undefined—A street where no bike route exists.
- Bike Lane—A designated area of the street that can be used by cyclists. Bike lanes are indicated using painted lanes or symbols on the street.
- Path—A mixed pedestrian and cyclist path that does not interact with vehicles, except at intersections.
- Segregated Bike Lane—A designated area of the street for cyclists that is separated from the vehicle traffic by a curb or other barrier.
- Suggested Route—A street where no bike route exists, but a future route has been suggested.
Suggested routes have the highest number of collisions, while paths have the fewest. Based on the counts for suggested routes and undefined routes (91 and 45, respectively), the majority of cycling-related accidents are occurring on streets that do not have an existing bike route.
Some of the collisions on bike lanes, segregated bike lanes, and suggested routes took place at intersections, so they are counted twice (once for each route type at the intersection).
The heat chart displays the number of collisions for each route type and year. The cells are styled with graduated colors, meaning lighter cells indicate lower numbers of collisions and darker cells indicate higher numbers of collisions. The Suggested Route row has the darkest cell for each year, meaning the highest number of collisions with cyclists always took place on streets with suggested routes.
- On the heat chart, click the cell for suggested routes in 2015.
The corresponding collisions are selected on the map and the legend.
- On the heat chart, point to the selected cell.
The pop-up indicates that there were 26 collisions on suggested routes in 2015.
- Press Ctrl and click the cells for suggested routes in 2016, 2017, and 2018. If necessary, click the map card and zoom in to better see the collisions.
The map displays the collisions on suggested routes for all years.
Three streets running east-west and two streets running north-south have the most collisions over the four years. Depending on your basemap and zoom level, you may be able to see the street names. Somerset Street West, Gladstone Avenue, and Wellington Street have the most collisions for streets running east-west, and Bank Street and Elgin Street have the most collision for streets running north-south.
To change the basemap, click the Basemaps button on the ribbon and choose a new basemap.
- On the heat chart, point to the cells for selected routes in 2016, 2017, and 2018.
According to the pop-up, there were 24 collisions in 2016, 24 in 2017, and 17 in 2018.
Given the high number of collisions on suggested routes compared to streets with existing routes, you'll recommend that the city add bike lanes or segregated bike lanes to the suggested routes, starting with the streets with the most collisions.
- Click the map to clear the selected features on the map and the chart.
Based on the colors on the heat chart, it appears that the number of collisions with cyclists decreased in 2018. However, the heat chart isn't the best visualization to see the trend in overall counts over time. You'll change the heat chart to a stacked bar chart.
- Click the heat chart to activate it. On the toolbar, click the Visualization type button.
A list of chart types appears.
- Click Stacked Bar Chart.
The heat chart changes to a bar chart showing the number of collisions involving cyclists by year. Each bar is divided by route type.
Based on the length of the bars, the total number of collisions involving cyclists was highest in 2016. The other years (2015, 2017, and 2018) had a consistent number of collisions, with only a slightly higher number of collisions in 2015 compared to 2017 and 2018.
Despite the total number of collisions remaining consistent for most years, there are changes in the route types from year to year.
- On the legend, click Segregated Bike Lane.
The map and chart update so collisions on segregated bike lanes are selected. Two streets in Somerset ward contain almost all of the selected collisions.
Based on the bar segments on the stacked bar chart, the number of collisions on segregated bike routes was low in 2015 but increased substantially in 2016.
Despite having a clear separation between vehicle traffic and cyclists, segregated bike routes have the second highest number of collisions in every year except 2015. You'll take a closer look at the spatial distribution of collisions on segregated bike lanes.
- On the chart, click the bar that corresponds to segregated bike lanes for 2015.
Three collisions are selected on the map.
Two of the collisions occurred at intersections.
- On the chart, click the bar that corresponds to segregated bike lanes for 2016.
The selection is updated on the map. According to the pop-up for the selected bar, there were 17 collisions on segregated bike lanes in 2016.
- Zoom in and pan around the map to examine where the collisions took place.
Ten of the 17 collisions took place at or near intersections. Two of the collisions took place at intersections with other route types.
- Examine collisions on segregated bike lanes in 2017 and 2018.
There were 16 collisions on segregated bike lanes in 2017, 14 of which took place at intersections. Four of those intersections included different route types. In 2018, the number of collisions decreased to 13, with 8 taking place at intersections, 2 of which included different route types.
- Clear the selection and save the workbook.
Despite changes in the number of collisions on segregated bike lanes each year, the majority of collisions take place at intersections. In total, 9 of the 49 collisions on the segregated bike lanes took place at an intersection with a different route type.
Even if you remove collisions that took place at intersections, 40 collisions took place on segregated bike lanes. That value is still higher than the values for bike lanes and paths, despite segregated bike lanes having a higher degree of separation between vehicle traffic and cyclists than painted bike lanes. Because the majority of collisions took place at intersections, you can recommend that the city research how to make intersections safer for cyclists (for example, by adding bicycle signals to traffic lights).
In this lesson, you used ArcGIS Insights to learn more about traffic collisions involving cyclists in Ottawa, Canada. You mapped and charted relevant data and interpreted the results to come up with steps the city can take to make cycling safer.
You can find more lessons in the Learn ArcGIS Lesson Gallery.