Changeable Message Signs and Speed Feedback Signs
This solar-powered changeable message sign used in Mill Valley, California, is adjacent to a school and is only operational during the school commute periods.
Permanently mounted changeable message signs are illuminated with messages or speed limits and are used to heighten awareness of speed limits in the school zone or to establish a lower speed during school crossing times. There are standard signs for school speed limit signing, and there are new innovations such as changeable message signs. Solar units are available for under $10,000 per sign, and non-solar units are sold for under $8,000. While the non-solar equipment is less expensive to purchase, it requires a hard wire connection to a power source, which can be much more expensive.
One type of changeable message sign is a speed feedback sign that shows YOUR SPEED and the SPEED LIMIT to alert drivers to their actual speed and the posted speed limit. Speed feedback signs can record traffic counts and are programmed via a Personal Digital Assistant. They work best if they flash or provide a SLOW DOWN message if drivers exceed a preset speed threshold. Occasional law enforcement is also needed at these signs. Speed feedback signs still need to be used with other standard speed limit signs placed in advance of or next to them.