Improving the Readability of the Beijing Subway Map for the General Public
Maps are widely used in different areas. And mapmakers often use colors as symbols to represent a amount of information. Now the universal design seems to be more and more important, which are inherently accessible to older people, people without disabilities, and people with disabilities. But unfortunately, most color maps are produced with little if any consideration of color vision impaired users.
In this project, an analyze of CVD (color vision deficiency)-simulated color scheme of the Beijing Subway Map results that the color scheme is not friendly enough for the reader with color vision deficiency. In order to improve the map’s reading efficiency and make it as a universal design, a new subway map was made based on some theories from the previous work and the procedure is described. The results of user test and evaluation with both original and the adjusted maps are presented.
Color vision simulation of the color scheme
Sim Daltonism is a tool which can simulate the color visions with various types of color blindness. Before conducting the simulation, every line’s name, color palette and color code were typed into excel so that data can be recorded.
Figure 1. Original Map
Figure 2 shows the results of the simulation. It can be seen from the picture that in each legend (except the normal version) there are several pairs of colors extremely closed.
Figure 2. Simulation result
All the colors in the legend were reordered under each impaired color vision category so that the similar colors could be easily found. From Figure 3 it can be discovered that in the Protanopia and Deuteranopia color groups, the color of Line 6 and Line 9 are much more similar to each other compared with other colors. In the Tritanopia color palette, the color of Line 4, Line 10 and Line 8 seem to be one color at the first sight. On the subway map, Line 10 interlaces Line 4 and Line 8, and Line 6 crosses Line 9. So the color should be designed as easily discriminated, in order to decrease the opportunities for making errors while users reading it.
Figure 3. Color reorder (A=Airport Express, B=Batong, C=Changping, F=Fangshan, Y= Yizhuang)
Most passengers often read the metro maps in the carriage or the metro station. But as the reason of insufficient illumination, the color readability of the map probably decrease.
Map Design
Based on the findings of the color vision simulation it can be proved that the color design of the Beijing Subway map is not friendly enough for the people with color visual impaired. Four aspects will be improved in the redesigned map:
1. Avoided to use the pair of colors which are extremely similar. For example, the color of Line 6 and Line 9.
2. Using distinct patterns in those line with low-contrast colors for the color vision deficiency, such as colors in the same hue or green and red. In order to decrease the amount of color using, apply a different thickness of lines in the design.
3. Content on the label should be clear and concise, and the size should big enough.
4. Each line’s pattern should be explained and displayed in the legend.
A redesign was produced that combines both colors and patterns, to avoid confusion between lines while retaining the quick recognition of colors. It is based on the findings of the color vision simulation. Each line’s color, pattern and label are listed in Table 1.
Table 1. Color, labels and patterns in the redesign
Here is the new map. Owing to that most of the old lines have already applied their color into the visual identity system, the change of the color is slight.
Results of evaluation
10 participants have attended the test and evaluation. The 4 versions of maps are displayed in Figure 5.
Compared with the old map, the new map enhances the readability based on the evaluation result. The labels and patterns have made the map more easily to read and much clearer than the previous one. But the redesign is still can not be taken as a universal design because of a lack of evaluators with color vision deficiency as well as the tiny amount of participants in the evaluation. So it can not be concluded that the design is better for all the general public.
For the test itself, it also contains some biases. The random start points can not guarantee the same degree of difficulty for finding the defined destination. And while doing the test, every participant was in a different reading environment with different levels of illumination. It would affect their readabilities indirectly, thus may result in a different scale of marks. So the test could have been designed more detailed to avoid some of these biases.
Some feedback gathered from the participants pointed out that the fonts size are not very comfortable to read. And also some participants thought that the white point in each stop in the original map could help to find the destination quickly. Beijing is a city which attracts a large quantity of tourists every day. So it could be considered to put some icons of attractions on the map, in terms of increasing the speed of finding the destination of those tourists. The work which can be done in the next step is to make an alternative design of the subway map and implement a better-designed test to get more significative data.
