Many decisions, especially purchasing decisions, rely on data. When you’re responsible for public safety and road safety, your decisions can affect people's lives.
To make an informed decision which best serves the needs of the public, always consider the bigger picture and be sure to dive into data being presented. If information appears questionable or irrelevant, you may want to take another look.
As the old saying goes, “A picture is worth a thousand words.” And when it comes to comparing the performance of various products, graphed data is often an effective means of quickly showing a reader how they stack up, right? Well, maybe not always.
For example, take a look at the graph reproduced below from a sales brochure. Note that the graph is reproduced as it originally appears in the brochure, except that the name of the publisher has been removed.
The graph is used in the context of the brochure’s message about the effects of sign sheeting orientation (the direction the sign is mounted vs. sheeting manufactured direction) on retroreflective performance.*
It looks like straightforward data that favors one product over another, but looks can be deceiving.
When presented with data visualized in this way, the common question is “What does the graph show?” But you should also ask yourself, “What does the graph NOT show?” Let’s take a closer look.
After a close inspection, you may be left wondering:
The list of questions could go on, but the point is this: a graph may give an impression of performance differences, but it can still fail to provide the whole picture.
When meaningful information is missing, it leaves room for false interpretations. So, to make informed decisions, always ensure the data you’re reviewing is complete, accurate and scientifically valid.
To learn more about retroreflectivity, check out “What is Retroreflectivity and Why is it Important?”
When you’re responsible for public safety on roadways, you know your decisions can affect people's lives. So, when you’re presented with an image of road signs with some dimmed (non-uniform) letters, you take notice.
We do too. And that’s exactly what happened when we saw the image in a manufacturer’s brochure. To us, something just seemed odd about it. We decided to investigate to find these exact signs and better understand what’s happening in the photo.
After some digging, we found them. This Google Maps link takes you to a ground view of the same signs in the daytime, so you can see for yourself the different angles from the photo could have been taken.
Now, take note where a photographer might have been standing for this angle.
Strangely, the photo in question appears that it may have been taken from the frontage road next to the main highway or perhaps from the nearby shoulder. While we can’t make an exact match, we’ve approximated the same pitch and perspective to help provide some context to the photo.
While the photo was intended to reinforce a story about how sheeting orientation affects the appearance of overhead signs, there are inherent problems:
Because critical decisions are made on the roadway, the perspective of the driver should be taken very seriously. We know the driver is on the road, what direction they’re traveling, where their headlights are likely to be—all of this information is critical to optimizing safety and driver experience in a maximum number of scenarios.
The photo may create an impression of performance differences, but it falls short of providing meaningful information given its estimated irrelevance to an actual driver on the highway.
You may have seen this image or even witnessed a spinning sign demonstration. Let’s shed some light on what it means and how it connects—or perhaps doesn’t—to the driver experience.
In this demonstration, two signs are displayed: one with one manufacturer’s reflective sign sheeting, and another with a competitor’s sign sheeting. Then both of the signs are spun.
As it spins, the competitor’s sign “blinks” between brighter and dimmer sections, potentially leading observers to believe that road signs in the field may blink too.
Immediately, you might wonder:
Let’s explore the concept in a comparable context: books.
Just like a fixed road sign, a book conveys information, and is typically read in an upright position.
If you turn a book sideways (change its orientation), it’s harder to read, and is therefore less effective in doing its job (communicating information).
With an “omnidirectional book”—one that would feature new letters and symbols that could be rotated—one could theoretically “spin” it to demonstrate how it could be read from an angle. While this might have a “wow” factor, the question would become: what problem does it solve?
Of course this is a ridiculous example, but it illustrates the false problem of the spinning sign demonstration.
A sign mounted to a post will not spin or blink.
Likewise, when you sit down to read, you position yourself and the book in a fixed position that’s most comfortable for you to read.
On the roadway, there are known factors. The direction of the sign is known, and it’s known how the sign will be positioned relative to vehicles.
With this knowledge, sign sheeting can be optimized for the driver’s maximum benefit. In the end, only the driver needs to be able to read these signs to make critical driving decisions.
To ensure the best driver experience, it’s recommended that all sign sheeting of the same color and on the same sign be oriented in the same direction (ideally in the 0 or 90-degree orientation). This ensures the best driver experience and finished sign appearance.
Disclaimer: Some photos and reference materials in this blog are from a competitive reflective sheeting manufacturer