Case study 1

iDrive™ 5.0 System

The upcoming iteration of BMW’s iDrive™ system, 5.0, is a 1440 × 540 LCD screen sized 10.5” × 3.94” for an effective resolution of ~137 pixels per inch (ppi). This is approximately twice the resolution of a traditional PC or Mac LCD screen but lower than current MacBooks with Retina screens (218
227 ppi), iPads (264324 ppi), iPhones (326401 ppi), and nearly all current Android phones (most are over 300 ppi and some eclipse 500). This does not mean that BMW’s screen technology is insufficient to display lovely type, nor does it mean that the current typography is illegible, but the font should be suited for its screen.

The Next Generation Of Idrive 8 1500x1000
image 1: iDrive 5.0

The current font used by BMW is BMW Global Pro, an international grotesque in the Helvetica mold, but with sturdier forms, often set tight with reduced spacing. This is a strong identity that affirms BMW’s reputation as a global leader in vehicles that engage the driver’s spirit while ensuring comfort, reliability, and safety. The message continues into the cabin with the iDrive system typography. Using image 1, I was able to deduce that the main typography (“Media/Radio”, “Communication”, etc) is set at ~36 points, yielding capitals ~45 pixels tall. This is likely more than enough for most applications, but I can see room for improvement. At this size, the main stems of the letters are about 4–6 pixels thick. Improvements could be made in the rendering of the letters through a technique called hinting which achieves crisper outlines by instructing the rendering engine what it can and cannot do.

Font Hinting Example
image 2: example of hinting

In image 2, the top row of text is unhinted while the bottom row is hinted. One can see that the upper line “spreads out” more into neighboring pixels while the bottom line has cripser, sharper outlines. It is difficult to tell from the image I have of the iDrive screen, but I suspect it would benefit from hinting.

One thing I can tell from the image is that the BMW Global Pro typeface is not the best choice for the screen. The counters – the open spaces in a letter, such as in an e or a – start to close up, especially when the text is set light on a dark background (light pixels bleed like ink would on paper). The letterspacing is also too tight. My recommendation here would be to create a variant of BMW Global Pro better suited for screen display. The counters would be opened, the strokes made simpler, and the letterspacing increased. Different forms of letters would increase legibility, too, such as a single-story a or adding a serif to the i to help distinguish from the l.

Case study 2

Heads-up Display

BMW was a pioneer in automotive heads-up displays when it added them to the 5‑Series in 2004. At first, the heads-up display was considered a luxury but the safety implications of keeping the driver’s eyes on the road are obvious. In designing a good heads-up display, the information must be clear, obvious, and simple. There is an old metaphor in typography known as the crystal goblet: imagine two goblets of the same wine, one ornate, wrought of gold, and one of pure crystal, simple and transparent. The crystal goblet is designed in such a way so as to not impede one’s experience of the wine. Good typography aspires to this: to be in service of the message. When the text is to be viewed at a glance, contains important information, and can affect a person’s well-being, the typography should be as unadorned and legible as possible while still being pleasing to look at. The heads-up display is the textbook example of this.

Hud 1
image 3: heads-up display

The same issues I note for the iDrive 5.0 system are exacerbated by the heads-up display. Familiarity is one of the greatest aids to recognizing text. The eye does not read letter by letter but by rapid jumps called saccades that chunk letters into wordlets or full words. When the brain is familiar with the language and context, reading speed increases. In using a GPS system, though, it is safe to assume the driver is not familiar with the area and so would not know street names. We cannot help the driver familiarize herself with the area in advance but we can make the letters and numbers simpler and easier to read. In particular, image 3 shows a BMW traveling at 96 km/h. At a glance, that could be 88 km/h. Or 66 km/h. The 6 and 9 in this font have very tight apertures at their tails.

image 4: heads-up display
image 4: heads-up display

With a heads-up display, it’s like a game of telephone: the user is already one step removed from the display, mediated by the screen. The reflection is an imperfect replication, so why make it harder by having difficult typography? It is good that BMW has designed with high contrast in mind, but the letterforms are problematic to my eyes.

Monotype, in collaboration with MIT’s Age Lab, has done studies on legibility and reaction times for drivers (and airplane pilots). To my knowledge, nobody has fully implemented the recommendations of these studies yet. BMW could continue to be a pioneer in automotive heads-up displays in using these studies with the aid of a typographic engineer.