While these two types can cross over, Illuminated Traffic Signs and Digital Traffic Signs aren’t necessarily the same thing.
Digital/Electronic and Illuminated Road, Highway, Traffic, Street Airport Signs
Digital guide markers are typically lighted with LED’s (Light Emitting Diodes) and may have a small section that shows a number or series of numbers and letters, such as you might see at some airports, or may be an electronic reader board with messages for oncoming motorists.
Illuminated Traffic Signs
Illuminated Traffic Signs, on the other hand, may include digital kinds, but may simply be a signpost that is lighted from below with directional lamps, giving it the appearance of being illuminated. They typically have a sensor that flips the switch on the lights as it gets dark and then reverses the process as daylight arrives in the morning.
As you can see, on the rail below the signage and to the outside of the service platform there are lights affixed to the rail that shine onto the reflective surface, making it highly visible at night, which is a good thing, especially if you’re new to the area or passing through.
Digital Traffic Signs
Digital Traffic Signs are different in that they use LED’s, as mentioned earlier, and can look like this. The one on the left is a “message center” type and is programmed remotely with a new message as needed…typically something like “Road Construction starting August 1st and Never Ending…hahaha” or the like.
The one on the above is generally programmed from a booth and will say something like “Open” or “Lot 2 Full” or similar. Obviously, they are more expensive than your standard aluminum panel road sign, especially the message center style…the one on the left, for instance, probably cost taxpayers in excess of $100K.
In the previous article I discussed standards for traffic markers with reflective sheeting which are set nationally by the US Department of Transportation (USDOT), or by local states conforming to the USDOT’s Manual on Uniform Traffic Control Devices (MUTCD). This manual gives all the regulations for various aluminum-based displays, but doesn’t offer regulations regarding LED types. However, any type used on an interstate or state highway will still need to be approved by your local authority.
There are many manufacturers in the US, but only a few that manufacture the big message center LED displays. A few more make the LED panel types. Due to the complexity of the message center displays, many companies can sell them as distributors and do.
Internally Illuminated Signs
One other type of internally illuminated signage is used almost exclusively at airports or public transportation facilities. It is standard ballast-driven fluorescent bulb lighted type with a decorated polycarbonate face, one or two-sided, similar to the one shown here.
Obviously, this type needs to have a power source, so it’s not practical under many circumstances to use this in rural area plus they’re considerably pricier than standard aluminum panels. They are also customized and are not covered in the MUTCD, but are typically regulated by local authorities. There are many companies that manufacture them, but any of them would need to be approved by the proper certifying authority.
Click here to check out more about digital and illuminated traffic signs.