Portland Vision Zero

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Why We Love It

The Vision Zero program aims to eliminate deaths and serious injuries on Portland streets by 2025. We love how this map helps city officials reach this goal by representing the problem geographically and thematically. It shows traffic crashes by category (pedestrian, car, bike) in a tabbed Story Map. Areas most prone to crashes are defined for each mode of travel. By clicking on intersections, you can see details-on-demand. This visualization helps determine where to prioritize improvements to reduce injuries and fatalities.

Why It Works

The clever use of hollow orange proportional symbols for fatalities and solid gray circles for serious injuries allows us to see subtleties that would have been masked had the data been aggregated. Reusing these colors in the charts creates a connection with the map and shows accidents over time. The simple color palette, in conjunction with a muted basemap, sets the tone and aligns with branding for the City of Portland and the Portland Bureau of Transportation. This map grabs our attention, feels approachable, and imparts knowledge.

Important Steps

Aggregate the data to the intersection nearest the crash location so patterns of crash incidents are easier to identify.

Match the right Story Map template to the needs of the story. The author used the tabbed layout as a data filter to allow for quick comparisons

Visually experiment with the size of the proportional symbols (circles) to convey the overall density of incidents without letting the largest symbols overwhelm the map.

The legend is critical to understanding this map (both categories and magnitudes). The custom legend, made in Adobe Illustrator, is put front-and-center to speed comprehension.

Requirements

Data

The map summarizes data compiled by the Oregon Department of Transportation’s Transportation Data Section Crash Analysis and Reporting Unit.

Analysis

The individual incident point data was aggregated in two ways. All incidents in the city were aggregated for the city-totals-by-year (chart), and across all 10 years. Crash incidents were assigned to the nearest intersection and summarized by mode and injury severity (map).

Time

It took 3 hours to aggregate the data, 8 to 10 hours to prepare the maps, and 4 to 6 hours to make the charts and legends then format them for the side panels.

Aggregate your Point Data

Tips

Never build more UI than the story needs. The simplicity of the interface brings focus to the data and flattens the learning curve.

Use the dark gray pop-up

Tips

Interactive maps allow details to emerge on demand, as the user needs them. In this case, pop-ups provide detailed information on incidents.

Network Analyst’s Service Area

Tips

Achieve an added level of polish by using a one-pixel stroke on the circles the same light grey as the basemap making it invisible unless two circles overlap.

More Information

Map Author

Erin Aigner

Erin Aigner

@PBOTinfo

The Portland Bureau of Transportation is a community partner in shaping a livable city. We plan, build, manage and maintain an effective and safe transportation system that provides people and businesses access and mobility. We keep Portland moving.

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