After eight hours of driving through heavy traffic, re-routed directions to avoid congestion, and a close call with the highway patrol, I was more than grateful for the bright glow of information projected onto my windshield.

The 2019 Lincoln Navigator I was driving from New York City to northern Vermont had a "heads/head-up display," or HUD, with navigation directions, driving speed, speed limits, the time, temperature, and other information superimposed onto the road ahead. The display worked just as well during the day or night, showing me which exit I should take or the speed I should drive. It immediately became an essential driving tool.

The Lincoln Navigator head-up display kept my eyes on the road. Image: lincoln All the information I need on the windshield. Image: sasha lekach / mashable

And yet the most advanced and tech-friendly car brand, Tesla, stubbornly refuses to include it. When the Model 3 was first announced in 2016, many thought it was Tesla CEO Elon Musk's chance to add it to his vehicles. But, nope — instead a sleek, minimalist design with only a 15-inch touchscreen appeared in the car.

On Tesla's online forums a divide has formed with some clamoring for the HUD tech and others defending Tesla's user experience design. Some even suggest third-party HUD projectors to install.

Now with the Model Y, murmurs about a HUD are resurfacing, but Musk is again dispelling any hope that he'll include the visual aid in his cars. Tesla reps referred to Musk's comments during a June interview with podcast Ride the Lightning as the company's latest stance on the technology.

“We discussed a HUD [for Model 3]. I’ve tried various HUDs and I find them pretty annoying. We felt that [Model 3] would increasingly go towards self-driving, and then you wouldn’t really care about having [information] on the windscreen. So, as things are approaching autonomy, why project things that you don’t care about on the [windscreen]?" Musk said.

HUDs are intended to keep drivers paying attention to the road and what's happening ahead of them despite the glut of information spewing from screens throughout the car. Instead of glancing over at the touchscreen next to the wheel, I could stare straight ahead while I drove the Lincoln, for example. The information I needed was all there, including turn-by-turn directions if I used the car company's built-in directions feature. (Even though Apple Car Play was available with navigation apps, using Google Maps directions wouldn't display on the HUD, only the center screen.)

A recent Liberty Mutual study of 8,000 American and Western European drivers found 67 percent of U.S. drivers admitted they used their phone while driving. During my day of driving the Lincoln, I had my phone away in a compartment and all my information plugged into the car. I didn't need it — not even for directions. The HUD played a huge part in that.

So many screens, but all you need is a HUD. Image: lincoln

Musk is skipping HUDs because he's hell-bent on autonomy and thinks the tech would be worthless in self-driving cars. Musk anticipates Tesla will have a robo-taxi fleet by the end of next year.

But we're not there yet — and Musk's estimates have a tendency to be belated and overhyped.

In fact, HUDs could even be helpful once cars drive themselves, said Derek Sellin, vice president of marketing at Rightware, which builds software for user interfaces and digital displays for cars.

He thinks HUDs of the future should "be married with other tech" like eye tracking and other driver information. If the car is in self-driving mode and the driver is looking out a window that's not the front windshield, a HUD is pointless. But if the same projection tech follows the driver's eyes and overlays information wherever they look, the HUD stays relevant and useful. In a mixed driving scenario, where a human driver needs to take over from the computer, HUDs could be crucial to quickly refocusing on the road.

HUD technology dates back to the 1980s and 1990s with the 1988 Oldsmobile Cutlass Supreme first debuting the tech to the public after earlier use in military vehicles. It can feel like augmented reality, but really the information is projected onto the glass windshield from behind the driver seat console. To stay relevant in 2019 and beyond, the assistive tech needs to add more to the driving experience than just putting information in your line of sight. HUDs of the future could sense if a driver is tired, distracted, or succumbing to road rage; track how long they've been driving; or notify the driver about whether there's a car crash up ahead.

Just because autonomous vehicles are coming doesn't mean HUD technology isn't improving. Instead, now's "the opportunity to provide a more holistic user experience" with relevant information on the windshield, side mirror, or elsewhere, Sellin said. As he put it, it should be "context sensitive," like when I was going over the 65-mph-limit and the screen in front of me projected that brightly and clearly.

Until my car is fully in charge, there's nothing annoying about having helpful information in a spot where I can see it without looking away from the road.