As a driver you must be able to see traffic signs, they need to be clearly visible both day and night. Traffic signs play an integral role in the road safety equation. They bring order to our road network, allowing us to navigate the system in relative safety and security by providing: information about the road conditions ahead, instructions to be followed at major crossroads or intersections, warnings and/or guidance to drivers and pedestrians and the proper functioning of road traffic. By law you are required to follow all road signs, not noticing or obeying them is your mistake. But what if you missed it? What if you couldn’t see it? The consequences can be drastic...even fatal!
Driving a vehicle is a demanding activity that requires your full attention, a mind-body action most people perform whose tasks rely primarily upon vision. If you can’t see, you can’t avoid potential threats. Therefore, it is safe to say that visibility is a major factor in safe driving, and improving our visual information systems along our roadways will have a major impact on the safety of all road users.
The significance of highly effective road signage cannot be undervalued as a primary road safety tool. Studies have found that increased sign visibility plays a major role in road safety that positively impacts the community navigating our roadway systems, be it motorists, cyclists or pedestrians. Road safety schemes involving improved road markings and signage, in all types of locations, lead to a safer travelling environment for road users. Simply put, more visible signs result in lower accident rates. Where more visible signs are installed, crash numbers have fallen 25% to 46% in three to six years.1
A study from the University of Iowa found a direct relationship between a sign’s brightness and a driver’s ability to see the sign and its message. Study participants were able to read and understand brighter signs substantially faster.2 This study suggests that brighter signs require less eyes-off-the-road time, leaving drivers more focused on the task of driving - an especially important advantage when driving at night.
Traffic sign technology has changed dramatically in the last few years, as breakthroughs in retroreflective science have been adopted around the world. Let’s look at the principle of retro reflection and how it works with signs to make our roadways safer. When headlights strike a traffic sign the light is reflected back to the driver in a cone shaped form. This cone of reflectivity or cone of returned light allows the driver to see the sign; the closer the driver is to the centre of the cone the brighter the sign appears. For drivers on the edge of or outside the cone, signs are dimmer and more difficult to see at night. Most retroreflective technologies also have some diffuse reflection which is essentially wasted light that is not reflected to the driver. The difference between high and low efficiency sheeting technologies is how much light they return to the light source. Higher efficiency sheeting returns more light back to the driver. Technology makes it possible to expand the cone of reflectivity both in terms of directing more light to drivers and by returning light in a wider angle. A larger cone of retro reflected light means that even drivers in four-wheel drives, utes, and semi-trailers at larger observation angles are still able to see bright clear roadway signs.
Watch the stop sign visibility demonstration video below that shows the difference in nighttime sign visibility due to different grades of reflective sheeting.
Using high performance retro reflective sheeting in the manufacture of traffic signage results in significantly brighter signs. 3M’s high performance full cubed prismatic sheeting, 3M™ Diamond Grade™ DG3 Reflective Sheeting helps night-time drivers get the critical visual information they need for a safer drive.
In the physics of prismatic retro reflectivity, three carefully angled surfaces reflect light back to its source. Truncated cube corners return only a portion of that light. 3M™ Diamond Grade™ DG3 Reflective Sheeting provides full-cube microprisms, this represents optimal performance in retro reflective technology, with optic elements that are nearly 100% efficient, resulting in sign sheeting that returns almost 60% of available light. With this technology our Diamond Grade DG3 reflective sheeting greatly increases the brightness of road signs, returning several times more light than glass beads and nearly twice as much light as truncated cube corner optics. 3M’s full-cube construction also accommodates the wide range of observation angles from different size vehicles and entrance angles. Even signs in the most disadvantaged locations perform better with Diamond Grade DG3 sheeting.
3M™ Diamond Grade™ DG3 Reflective Sheeting is not only one of the most efficient sheetings in the field under typical conditions, but it also utilises unique technology to optimise performance in a changing driving environment. Count on innovative Diamond Grade DG3 Sheeting to improve traffic sign visibility for all drivers and create a more positive driving experience through safe, efficient travel with the following benefits:
Turn black spots into bright spots - Black spots are places where the number of crashes is higher than average. Often the reason for black spots is the physical configuration of the road or intersection, such as:
Accommodate older drivers - According to data from World Population Prospects: the 2017 Revision, the population aged 60 years or over is growing faster than all younger age groups and is expected to more than double by 2050, rising from 962 million globally in 2017 to 2.1 billion in 2050. Vision, which provides 85% of the information necessary to drive, deteriorates with age, so an aging driving population creates the need for more visible road signs. Older drivers:
Optimise performance from many angles - Vehicle size affects observation angle and reflective sign performance because different sized vehicles create different observation angles between the headlights and the driver’s eye level. Heavy vehicle traffic has increased significantly over the years, and drivers of trucks are especially affected by reflective sign performance since the angle between the driver’s eyes and the headlights is significantly greater.
Retroreflective efficiency for low cut-off headlights - Visually/optically aimable (VOA) headlights reduce glare for oncoming drivers, but also dramatically reduce reflective sign visibility at night compared to conventional headlights. These headlights can reduce the illumination of signs by as much as 48% in common sign configurations. As more cars come equipped with VOA headlights, drivers need to compensate for decreasing amounts of light directed at signs.
Driver safety is our top priority, with the highest luminance values at the distance that matters most, 3M™ Diamond Grade™ DG3 Sheeting helps to reduce crashes and fatalities. To see first hand the power of how better visibility signage can increase safety, register for an in-office demonstration. We would love to come and see you and your colleagues and run a workshop around the Science of Advanced Signage. We can tailor the workshop around any or all of the topics listed below:
For more information about reflective sign sheeting and performance levels to meet the needs of your specific application view our Traffic Signage brochure, explore our website, or contact your 3M Transportation Safety Expert.
1. Ripley, D.A, Howard R. Green Company, ITE AB04H313, Quantifying the Safety Benefits of Traffic Control Devices—Benefit-Cost Analysis of Traffic Sign Upgrades, 2005 Mid-Continent Transportation Research Symposium Proceedings.
2. Schell, T., Yekhshatyan, L., Daiker, R., Konz, J., Effect of Luminance on Information Acquisition Time and Accuracy from Traffic Signs. Paper accepted for presentation and publication, Transportation Research Record, Journal of the Transportation Research Board, 2008. Full report available at http://ccad.uiwoa.ded/ opl/projects/luminance