Fixing Tesla’s Big-Screen Graphical User Interface

My wife has had her Tesla Model 3 Long Range for almost a year now. Mechanically, it’s a marvelous car, a dream to drive. But its big-screen graphical user interface (GUI) spoils the driving experience.

When first learning to drive the car, I would have given the GUI a C+ grade. Now, after nearly a year of use, I would give it a D. Every time I have to use it, I hate it more.

In keeping with Elon Musk’s world-class arrogance, Tesla maintains no way to offer GUI feedback that I could find. So I’m writing this post in the hope that someone in Tesla’s management will discover it and fix the damn GUI. Here are my suggestions how:

1. General design principles. First, the programmers seem to have organized the GUI by abstract categories, before even acquiring much experience driving the car. At very least, the person in overall charge of the GUI should have owned and regularly driven a Tesla for at least a year, and have continuously improved the GUI accordingly. The results today suggest that that was never done.

Second, the GUI design must take into account the mechanics of the driving experience. Because of their big batteries, Teslas are extraordinarily heavy, weighing in at over 5,000 pounds with the size of a compact car. To add to that, their tires are hard (to reduce rolling resistance and extend range), and the steering and suspension are tight to simulate sports-car driving.

As a result, the Tesla driving experience is extraordinarily bouncy. This makes hitting tiny icons—let alone sliding-scale adjustments—while the car is moving a difficult exercise in hand-eye coordination.

This is so even for the passenger. For the driver, every use of the GUI while driving is a challenge and a safety hazard.

To reduce this annoyance and danger, no screen icon, slider or other control should be less than a centimeter in any dimension (about the width of a finger). All vernier adjustments not on the rotary steering-wheel dials should look the same, and all should appear in the same screen position, with a range of numerically labeled buttons, each no less than one centimeter square, running from 0 (off) to 10. (It might help to have a button that also puts HVAC adjustments on the steering-wheel rotary dials temporarily, say for ten seconds, so the driver could adjust the temperature and/or airflow without taking eyes off the road.)

Finally, programmers may think that tiny icons are cute, but they leave users guessing as to what they control, and how. Every icon should have an English label below it, translatable into whatever language is the driver’s native tongue. (Software makes this easy, and Apple seems to have no trouble doing it.) If programmers feel this clutters the GUI, they should make it a software-controlled user option, perhaps to be discontinued after a learning period. (I still find myself guessing at the icons for the HVAC almost a year later.)

2. Get rid of hand gestures entirely for GUI control. They may be practical on an iPhone, when you’re standing steady on the ground and your entire attention is focused on a few square inches in your hand. When you’re driving a car at 70+ MPH and the car is bouncing as a Tesla does, they’re frustrating and dangerous. So this putative aesthetic embellishment becomes an annoyance and a hazard. There’s nothing that you can do with hand gestures that can’t be done with buttons more easily, precisely, reliably and safely.

3. Put controls for all mechanical elements on the home screen. The purposes of Tesla’s big main screen were to save the cost of mechanical controls and allow simple and cheap modification. But the GUI often requires multiple screens, icons and gestures to do a single thing. The most egregious example is opening the glove box, which often takes hitting two buttons on opposite sides of two different screens!

The home screen should have language-labeled icons to activate every mechanical feature of the car (except the doors from inside, which have their own mechanical buttons). This includes: all interior and exterior lights, the trunk, the frunk, the door locks (all, driver’s, front and back separately), the glove box, the charge port, and the side-mirror folding and unfolding (preferably a toggle). The driver's personal adjustments—seat position, mirror positions, steering wheel, etc.—should have a separate icon on the main screen.

The HVAC controls, including heated seats and steering wheel, should have their own screen, reached with a prominent button on the home screen. Perhaps there should be separate virtual buttons for driver's side, passenger's side and back seats.

The airflow part of the HVAC should have a separate subsidiary screen with an entry button on the home screen. So should the radio, cell phone, and external audio interface (bluetooth). And every other screen but the home screen should have a big icon for the home screen, all located in the same place, probably the upper left.

4. Reorganize the home-screen buttons in a way that makes sense for the driver and passenger, not the programmer. The most important features for day-to-day use are mechanical-element controls, navigation, HVAC, audio controls (including radio, Web services, cell phones and bluetooth), charging controls, and charging-station location, in roughly that order. All these things should have prominent entry buttons on the home screen, placed in order of probable frequency of use. Better yet, the positions of icons on the main screen should be user-adjustable, like the icons on an iPhone.

5. Make navigation simpler to access and use. After nearly a year of use, it’s still a chore for both of us to find the address-input screen (which now requires two buttons and a gesture) for GPS guidance and to control the volume of voice guidance or turn it off. It shouldn’t be that hard.

The home screen should have a big, prominently labeled button for inputting a navigation address. Preferably, it should lead to an entire screen devoted to the address, showing charge stations along the way (including must-visit ones!). There should be button-triggered options for multiple stops, choosing which suggested charging stations to visit, showing a map side-by-side, and turning the audio guidance on and off. A full-screen map should be a separate option, automatically showing the specific address in a side box. And every map should have a compass direction/heads-up direction toggle button, clearly marked.

6. Don’t use the GUI as a marketing device. The early use of the audio-source selection screen to market various paid subscription services only enraged us. Isn’t that a bit tacky in a $60,000+ car? (Tesla since appears to have stuffed the marketing into subsidiary screens.) Any marketing on the GUI should be by request only, clearly marked with a dedicated button. And BTW, the radio station list should tune to each station when you touch it in the list.

7. Provide a feedback mechanism right in the car. Most big-business Websites now provide online feedback mechanisms, often with buttons on each Web page. Tesla would do well to emulate that customer-friendly practice.

A feedback mechanism right in the car would motivate users to provide feedback right at the point of frustration, while the source of trouble is still fresh in their minds. If coupled with rudimentary AI, it could let Tesla’s engineers tally customers’ “votes” for modifying specific systems without the need for special surveys.

The purposes of having software control most small mechanical functions is flexibility and continuous improvement, right? So why not actually implement continuous improvement, at customers’ behest, while Elon Musk is distracted with his latest toy, Twitter? Who knows, the management that actually makes the cars might achieve continuous improvement by inaugurating a (gasp!) user focus group. What a concept!

Endnote on the iPhone App. The foregoing comments apply only to the Tesla’s own internal big-screen GUI, not the iPhone App. Unfortunately, I hate the iPhone App even more.

The App’s organization is mind-bogglingly frustrating. Often features seem not to work for no apparent reason. No feature that I could find tells you whether or not the App is actually connected to the car. So I recently searched the App’s charging feature for the car’s current state of charge in vain (perhaps because the App was not connected). The App should show connection or not on every page; and it should be organized by the things that remote users are most concerned with: (a) locking status and unlocking action; (b) charging status and progress; and (c) internal temperature control.

At least the App does let me into the car, when the phone is close enough to it. There I can access the big screen. But my general impression is that Tesla management inappropriately mixed programmers with computer/machine and cell-phone experience and somehow consistently got the worst of both worlds. (Hence the overuse of gestures and tiny sliders in a bouncy car.)

The best that Tesla could do now is overhaul the big-screen GUI and then get the App to reproduce the same user experience as closely as possible. Consistency may be the hobgoblin of small minds, but it would make both learning a new system and routine day-to-day use easier.


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