While these two types can cross over, Digital Traffic Signs and Illuminated Traffic Signs aren’t necessarily the same thing.
Differences Between Digital Traffic Signs and Illuminated Traffic Signs
Digital Types 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 can also be electronic reader boards with messages for oncoming motorists.
Illuminated types, on the other hand, may include digital kinds, but may simply be a sign 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.
Typically, illuminated signpost looks like this. 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 them highly visible at night, which is a good thing, especially if you’re new to an area or passing through.
Digital traffic signs are different in that they typically use LED’s, as mentioned earlier, and can look either look like this…
…..or like this…..
They like the one above are a “message center” type of sign that is programmed remotely with a new message as needed…typically something like “Road Construction starting August 1st and Never Ending…hahaha” or the like.
They are similar to the one on the right are 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 panels, especially the message center style…the one on the left, for instance, cost taxpayers in excess of $100K each.
Who to Check with Regards to the Regulations in Your State
In the previous article I discussed standards for reflective road signs 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 traffic signs, but doesn’t offer regulations regarding both digital and illuminated types. However, any kind used on an interstate or state highway will still need to be approved by the state DOT or USDOT.
There are many road sign manufacturers in the US, but only a few that manufacture the big message center LED displays. A few more make the panel-type LED. Due to the complexity, however, many companies can sell them as distributors.
Internally Illuminated Signage
One other type under internally illuminated traffic signs is used almost exclusively at airports or public transportation facilities. These are a standard ballast-driven, fluorescent bulb, internally lighted signage with a decorated polycarbonate face, one or two-sided, similar to the one shown here.
Obviously, they need to have a power source, so it’s not practical under many circumstances to use this type in rural areas, plus they are considerably pricier than standard aluminum ones. They are also custom types and are not covered in the MUTCD, but are typically regulated by local authorities. There are many companies that manufacture them, but all of them still need to be approved by the proper certifying authority.
Click here to check out production of digital and illuminated traffic signs.