The report released last month has shown that there are less-invasive alternatives to speed cameras and speed bumps. The study focused on two innovations, LED stop signs and optical speed bars both of which were found to have "traffic calming" effects without any downside beyond the cost of implementation.
The LED stop sign is designed to improve visibility - especially at night. Researchers attempted to collect data before and after the signs were installed to evaluate whether the $1600 solar-powered devices were effective in encouraging people to stop, but different observers failed to agree on what constituted a safe stop. The study then could only focus on observed reductions in speed leading up to the sign.
However, the optical speed bars (fancy term for horizontal lines) proved far more successful. By creating a visual sense of the speed for the driver, these horizontal lines have resulted in a decrease in speed of between 4 and 12 percent (2-5 MPH) on roads with a speed limit under posted by at least 5 MPH. This is based on the concept that conventional line markings can sometimes mask excessive speed, providing a visual cue by which to judge speed has increased driver awareness and resulted in an overall reduction of speed.
Expanding on this concept, by decreasing the distance between these lines, the researchers have been able to create an illusion of acceleration thereby causing driver's to slow down. This would be especially useful in school zone applications.