New Research Highlights Role of Luminance in Information Acquisition
Have you ever found yourself straining to read
a traffic sign that wasn't quite legible? Have
you ever missed an exit or a turn because you
couldn’t read a sign until it was too late to take
safe, appropriate action? Well, researchers at
the University of Iowa’s Operator Performance
Laboratory set out to study how luminance
provided by roadway signage plays a role in how
quickly we can process relevant information that
tells us which driving tasks are required.
The study, entitled Effect of Luminance on
Information Acquisition Time and Accuracy from Traffic Signs, was selected for presentation
at the recent 88th Transportation Research Board Annual Meeting in Washington D.C. A link
to the full report is included below.
In summary, the study found that:
- Increasing sign luminance provides faster information transfer from signs to drivers.
- If viewing time is limited, higher sign luminance and/or larger sign size provides more
accurate sign reading.
- Brighter signs decrease sign reading times and, therefore, are expected to reduce
eyes-off-the-road time. Eyes-off-the-road time is the primary characteristic of interest in
automotive safety, as driving safety is compromised if one is not watching the road.1
This research comes at a time when state departments of transportation across the U.S.
are looking for ways to improve guide sign visibility and save taxpayer dollars. Many are
finding one solution that helps achieve both goals by upgrading to guide signs made with
high performance reflective sheeting, while at the same time cutting maintenance and energy
costs by turning off guide sign lighting. The Hawaii Department of Transportation is one such
agency, having recently replaced signs on the Moanalua Freeway with 3M™ Diamond Grade™ DG3 Reflective Sheeting and eliminated sign lighting. They expect savings of $14,000 per year
in electricity and $30,000 in maintenance.
To help demonstrate the benefit of high-performance sheeting in a fun, engaging way, 3M put
together a web-based simulator. Go take the Full Cube Challenge today at www.3M.com/tss/fullcubechallenge!
Link to Iowa Study: http://www.ccad.uiowa.edu/opl/projects/luminance/
1 Dewar et al. Human Factors in Traffic Safety
