Research conducted by SML confirms 85% of drivers have no idea how fast they are going. A reminder with an accurate, highly visible speed display brings this 85% into compliance with speed limits in work zones, the neighborhood, or in the always dangerous school zones.
The Texas Transportation Institute at Texas
A & M University, the University of Nebraska, the University of Kansas,
and Iowa State University all confirm the long term speed reductions with
highly visible radar speed displays. Unfortunately, many municipalities and
departments of transportation don’t read or listen to the wise advice
of proven research. They buy the smallest and cheapest radar display their
budget will allow. They then scratch their heads wondering why they don’t
slow traffic. They try to buy safety on the cheap! Authorities wouldn’t
buy bullet proof vests for officers if they didn’t stop bullets. Why
then do they buy radar displays that don’t slow traffic? They don’t
do their homework! To work, a radar speed display must be large enough to
be seen! Iowa State University concluded 18” high numeral displays
had little or no effect on interstate speeds.
The reason is the numbers were too small to be seen and recognized by drivers at 70 mph. Interstate signs are large for a reason. They must been seen. Research by SML and others concludes the amount of speed reduction is in a direct proportion to the size and legibility of the speed display’s numbers. Go small and get small speed reductions. The City of Phoenix when comparing speed displays for their school zones came to the same conclusion. At city speeds, 18” high numbers appears to be the right choice. Any size less is wasting taxpayer money. The most effective radar displays always have a white strobe which flashes at drivers when they exceed the pre-set limit as seen above. Displays must have high intensity leds and not flip panel numbers. They must be accurate and measure speed down to one mile per hour. They must do one thing and one thing only...show speed! Many departments of transportation and local communities think it best to have displays that show messages in addition to showing speed. They theorize they are getting more for their 
money. This is safety wrong! A Stop sign says one thing...STOP and a radar display must only show speed. The Stop sign doesn’t also show “Eat at Joe’s.” It’s there to do one thing...stop drivers. One embarrassed department of transportation was featured on the local five o’clock news. The speed display said “Your Speed Is” and then took five seconds to show an incorrect speed.
The news crew ran twenty times at the speed display and each time it showed the incorrect speed. The display’s radar must be what we call directional radar. It only shows the speed of approaching vehicles and not the 18 wheeler in the opposite lane. It must be either K or Ka band and most definitely not X band as drivers with radar detectors will ignore an X band false alert. They think its coming from the automatic door opener at the supermarket. There is always one negative person sitting in the back of the city council room or at the school board meeting. They say the display’s effectiveness will only work until drivers ignore it. Not so says all the research! Do your homework before you make a safety mistake! Buy safety smart!
BIGGER IS BETTER
