Once just the home for a cluster of other essential instruments, the dashboard has become one of the weapons carmakers use to sell machines that have increasingly become computers on wheels. Thanks to their willingness to pull all the instruments and other user-interface functions into LCDs across the dashboard and centre column, the layout in front of the driver is not all that distant from the multiscreen layouts used by financial traders.
Safety-focused organisations, such as Euro NCAP, see the need to slam the brakes on this migration. There are clear manufacturing-efficiency advantages to OEMs in converting a bunch of separate mechanical knobs and switches and panel-mounted instruments into programmable functions on one or more large touchscreens. But the potential for distraction increases if drivers have to look away from the road to look for specific controls.
While Euro NCAP does not have legislative power, the group aims to use its scoring system to dissuade car makers from putting the controls for a range of driving functions, including the windscreen wipers and air-conditioning, onto these big touchscreens. From the beginning of 2026, the planned changes to the rating scheme will reward those that provide more traditional physical switches for those functions.
“This protocol will encourage the safe operation of the vehicle, by evaluating both how controls are operated…and their ease of use,” the group said in a statement. “A poor result in the new General Vehicle Controls assessment will not directly prevent a vehicle from achieving a five-star rating, but it will be harder.”
The group sees the protocol as a first step to avoid distraction in the design of user interfaces and will look at other ways to score interaction design over the following years.
For other functions, car makers are looking at other ways to deal with the potential for distraction but still get the chance to sell more display-focused options to buyers, whether they are for driving or entertainment for the passengers. The centre column is an obvious location to place a large flat-panel display that can display navigation and other information that is not absolutely safety critical. But it suffers from the same distraction problem as for the controls being moved back to dedicated mechanical knobs and switches. To handle that problem, OEMs now look favourably on the answer found by the aerospace industry: move to a head-up display (HUD) projected into the pilot’s view.
Market analysts see this part of the automotive sector growing about 25% a year into the next decade, passing from a little over $1bn in 2021. By the end of last year, more than a hundred models from car makers around the world had at least basic head-up projectors offered as trim options. These comparatively simple systems show speed together with turn-ahead symbols and speed limit indications.
The next phase
Many of the lower-end HUDs project the image from an LCD onto a thin piece of transparent plastic mounted on the dashboard between the steering wheel and the windscreen, with some choosing to reflect off a film on the windscreen itself.
A recent trend in luxury cars is to use so-called panoramic HUDs. These project onto a darkened strip at the bottom of the windscreen. That change helps improve contrast. For OEMs like BMW it also feeds into the next phase of HUD. Their displays will combine the lower strip with augmented-reality (AR) animations overlaid on the view of the road ahead.
Similarly, Audi’s Q4 e-Tron paints a blue arrow over the road to guide the driver in the right direction. The AR animations will back up the driver-assistance systems by indicating when the driver is getting too close to the car in front.
The more advanced HUDs place major demands on brightness from the display elements. Most designs today use backlit LCDs to project an image though the quest for brightness in higher-end vehicles may push vehicle designers to opt for microLED arrays, which are currently more expensive because of the painstaking assembly process needed to place the individual chips onto a substrate.
According to Eric Virey, technology and market analyst at Yole Intelligence, in the wake of Apple’s decision to ditch microLEDs for its smartwatch products, the automotive sector holds out hope for a large market that provides a path to optimising cost. But he notes, “high costs and an immature supply chain are delaying adoption”.
The AR HUDs rely on stereoscopic tricks to deliver a sense of depth to the driver, which not only increases the complexity of the projection electronics but their size. This leads to the same problem that afflicts VR headsets: the vergence-accommodation conflict. The distance mismatch between the apparent 3D of the icon and where it reflects on the windscreen leads to discomfort in long-term use, which is far from desirable for safe driving.
Above: A simulation of an automotive display using holography
One option may be to use actual 3D projection through holography, which is moving to where it could be a viable option. The same kind of LCD panels used for today’s HUDs lend themselves with a few modifications to the detailed control over the phase of coherent light beams from a laser that is needed to generate the interference patterns that generate holograms. There are challenges in the amount of processing power needed for holograms.
Another problem may exacerbate this overhead: the laser speckle that characterises holographic images. Speckle could be as difficult for drivers to deal with as the mergence-accommodation problems of stereoscopic displays. IDTechEx research director Xiaoxi He says dealing with speckle will probably delay the commercial introduction of these types of AR HUD. However, there may be ways round the speckle problem.
Additional computation to adjust the image from frame to frame may help. Cambridge-based startup Vividq claims to have developed methods to control speckle as part of its work to develop holographic AR glasses, as well as automotive HUDs. The company also believes it can use standard LCD panels to modulate the light rather than the phase-only liquid-crystal on silicon (LCOS) devices used in existing holographic projectors. According to He, time and spatial multiplexing can help reduce speckle with lasers. The other option is to conventional LEDs, as these emit partially coherent light, though that may degrade image quality. It is also a technique that is far less mature than existing laser-based holography.
Other parts of the supply emerging include a proof-of-concept shown at the Consumer Electronics Show in Las Vegas at the beginning of the year resulted from a recent three-way partnership between Eastman Chemical, Covestro and UK-based Ceres Holographics. This prototype laminated specialised films for reflecting holographic images in panels 400mm across onto the vehicle windscreen.
Though AR HUDs usage is likely to increase in high-end models, He and other analysts see it remaining as a niche compared to a larger conventional HUD market.
Figures from S&P Global Mobility suggest the market size for the AR versions to be less than a tenth of that for regular HUDs in the second half of the decade, partly because of the large amount of space needed under the dashboard to hold the projection optics for stereoscopic systems. Reducing that from around 20 litres will likely help drive the use of holography, as long as those systems can achieve high brightness and image quality.
The long-term picture is that, while some key functions will probably go back to traditional physical controls, other parts of the traditional dashboard will melt into the windscreen.
