To better understand how to design effective bus maps, we asked people about how they use and understand bus maps. Roughly 150 people from Nelson\Nygaard, Perkins & Will, public transit agencies, and transit-focused online communities responded to an online survey which attempted to answer three key questions in map design:
How do people understand the purpose of maps?
What makes a map clear and coherent?
What design elements work well?
The survey asked people to describe their understanding of various styles of transit maps, to outline their impressions of maps of differing complexity, and to assess the strengths and weaknesses of individual map design elements.
Bus maps should be easy to understand. Viewers need to know what they're looking at in order to make decisions about how to use a bus network. Maps that are difficult to make sense of or whose purpose is unclear are a detriment to the transit rider experience.
Our survey asked people to describe how well they understood three common styles of transit map. These maps varied in graphic complexity and the level of background detail they provided. Broadly, we found that more people understood a map with a moderate amount of background detail than maps that were either very simple or very detailed.
65% of survey respondents said they understood this map and thought others would too. 29% said they understood it but thought others would not. Respondents wanted to see more geographic detail to orient themselves and wanted clearer indications of line interchanges.
86% of survey respondents said they understood this map and thought others would too. A few respondents wanted to see additional detail in the form of roads and route frequency depictions but many liked the map's bold emphasis of transit lines with supporting geographic reference points, namely bodies of water.
Geographically accurate maps
Fewer people found it easy to make sense of this detailed geographically accurate map. 44% of survey respondents understood this map and thought others would. 32% understood this map but thought others wouldn't. 22% didn't understand this map and thought others would not. Many survey respondents expressed a desire for greater simplicity and clarity and a greater focus on the transit routes rather than the entire regional geography.
People seem to better understand moderately distorted maps relative to schematic or geographically accurate maps.
People like some level of background detail in maps to help them orient themselves geographically.
People want to see transit lines with background details to provide orientational context, but they want transit lines to be bold and easy to follow.
Image: transitmaps.net via Transmilenio
Image: Westchester County Bee-Line
What makes a map clear?
Getting complexity right in maps is a balancing act. Maps need to provide just the right amount of information to be useful to viewers but not so much that they become confusing. Creating clarity is key to achieving this balance. Clear maps make it easy for viewers to find what they're looking for specifically, and to understand how the entire bus or transit network works together. Unclear maps place too much of a burden of interpretation on a viewer, diminishing their overall transit riding experience.
Our survey attempted to ascertain what people perceive as the ideal balance of information in a map. We asked people to assess the same map of a hypothetical bus system at various stages of complexity and to describe what made it clear or unclear to them.
Bus lines only
37% of survey respondents found this map to be clear. Many felt that there was too little background detail for them to orient themselves within the map.
Bus lines + streets
50% of survey respondents found this map to be clear. People who did not find it clear generally expressed support for the addition of streets but wanted to see more points of interest.
Bus lines + streets + natural landmarks
66% of survey respondents found this map to be clear. Many respondents wanted parks and bodies of water to be labelled.
Bus lines + streets + natural landmarks + major buildings
50% of survey respondents found this map to be clear. Many respondents felt that there was too much background information and questioned whether or not the addition of major buildings was helpful.
More people find maps with bus lines, major streets, and some natural features clearer than maps with higher or lower levels of visual complexity.
Map viewers value labels on secondary or tertiary elements such as parks and bodies of water.
Individual design elements can make or break bus maps. Color schemes, font choices, line widths and offsets, and map orientation all impact the experience of a map viewer and can have a significant impact on a maps efficacy. Even well designed maps are less likely to be effective and appealing if they fall short on some of these key design elements.
Our survey attempted to understand which design choices commonly applied in bus maps are effective and which are not. It asked participants to indicate their preference for different styles of key design elements such as label fonts, background color schemes, and line widths. The findings, presented below, offer some empirical insight into which design elements are likely to appeal to the greatest number of people viewing a bus map.
Gotham X Narrow
Gotham X Narrow
Light Grey Background
Moderately Thick Lines
People want a balance of background detail and primary visuals
62% of survey respondents prioritize a careful balance of background detail and important visual information. 21% want to see only important visual information and 16% want to see a highly detailed map.
People value some design elements above others
When asked to rank common map design elements, respondents responded as follows:
Sans serif fonts are much more popular than serif fonts
66% of respondents prefer sans serif fonts in maps. 31% had no preference and only 3% preferred serif fonts.
Gotham X Narrow for dominant map labels
When asked to choose their preferred font for dominant labels from among 8 fonts commonly used by Nelson\Nygaard in maps, 30% of respondents indicated a preference for Gotham X Narrow. 20% indicated a preference for PW Centra. Other fonts were not ranked as highly.
Gotham X Narrow & Bahnschrift for secondary map labels
When asked to choose their preferred font for secondary labels from among 8 fonts commonly used by Nelson\Nygaard in maps, 20% of respondents indicated a preference for Gotham X Narrow and 20% indicated a preference for Bahnschrift. Other fonts were not ranked as highly.
Bright colors for bus lines
When asked to choose their preferred color scheme for bus lines from a set of bright, dark, pastel, muted, or monochromatic color schemes, 62% of respondents indicated a preference for bright colors. Pastel and muted colors each received about 15% support. Notably, not a single respondent indicated support for monochromatic lines.
Light blue for water
When asked to choose their preferred water color among light blue, dark blue, soft blue, grey, or white, 59% of respondents indicated a preference for light blue. 30% indicated a preference for soft blue.
Bus maps frequently feature white, grey, or beige backgrounds. When asked to choose their preferred background color among white, light grey, dark grey, and beige, 71% indicated a preference for white. 23% indicated a preference for light grey.
Thicker widths for bus lines
When asked to choose between very thin, thin, moderate, or thick line widths for bus lines, 53% of respondents prefer moderately thick lines and 45% prefer thick lines.
Slight offsets for route lines
When asked about their preferred distance to offset parallel route lines from one another, most respondents favored using a minimal distance. 57% prefer a slight line offset and 27% prefer a gapless offset with no visible gap between lines. Wider offsets were not popular.
Show time and distance on scale bars
When asked to choose between scale bars that show distance and some mode of travel time separately, scale bars that show distance and travel time together, or to indicate whether they prefer not to see scale bars, a plurality of respondents (37%) indicated a preference for scale bars that show a combination of distance and travel time.
Map rotation is acceptable
Many bus maps are rotated away from true north in accordance with local understandings of orientation or to better fit a map to a page. 74% of respondents felt that it is acceptable to rotate a map away from true north.
Most people want to see a reasonable balance between primary visuals and background elements.
People gravitate towards simple, plain design elements such as white backgrounds, sans serif labels, and thick transit lines. While preferences vary more widely for some design elements than others, these findings suggest that less complex design choices are more appealing to a wider audience than more complex design choices.