The federal government recognizes the superior communication value of EMCs and uses electronic information panels on many freeways to warn drivers of possible hazards. Its use of portable electronic warning signs at construction or accident sites is also increasing.

The sophisticated hardware that is now available makes maximum readability possible for the driver. Airports and highway departments are developing expertise in positioning and sizing of these signs to enable the driver to read, react and move through traffic with optimum safety.

Electronic message centers are not a distraction to drivers; it is quite the contrary. Their exceptional readability and conspicuity means that EMCs actually increase driver safety. The federal government and other reviewers, after conducting numerous studies, analyzing court cases, and reviewing the available literature, have concluded that signs and electronic message centers, if used properly, are traffic safety enhancement devices.

The 1958 Federal-Aid Highway Act established federal controls for signs illuminated by flashing, moving or intermittent light. The Federal-Aid Highway 1965 Act did not contain any reference to lighting controls. However, Federal/State agreements were entered into with all States referencing lighting restrictions on signs in commercial or industrial areas, based on customary usage.

In 1978, the Surface Transportation Assistance Act amended the highway beautification law to allow on-premise electronic message centers along the Interstate and Federal Aid Primary road systems, subject to individual state law, so long as those signs do not contain flashing, intermittent, or moving lights. Variable message signs, whose content can be changed or altered on a fixed display surface, are recognized by the federal government as different from the regulated animated signage, which mimic movement or have high-intensity flashing lights in order to grab the viewer's attention.

In a 1980 study commissioned by the Federal Highway Administration, researchers Ross Netherton and Jerry Wachtel set out to prove electronic variable message signs were unsafe. They concluded, however, that no credible statistical evidence existed to support the conclusion that electronic or variable message centers negatively impacted road safety. Their report also said that roadside signs provided a stimulus that helped maintain driver alertness, and increased safety by combating "highway hypnosis."

Several states have conducted studies on the safety of roadside signs, including EMCs, and none have found an increase in traffic accidents - and in some cases found a significant decrease in accidents - related to the signs. Furthermore, nine leading insurance companies were surveyed, and all indicated that they had never received an accident claim involving an advertising sign.

Richard Schwab, former Federal Highway Administration program manager for research on highway visibility and night driving safety and Fellow of the Illuminating Engineering Society of North America, conducted an extensive study that concluded EMCs could not be linked to traffic accidents or any reduction in traffic safety.

In 1996, the Kentucky Supreme Court struck down a state statute that prohibited signs near highways if they contained or included "flashing, moving or intermittent lights except those displaying time, date, temperature or weather …." The court said the state had failed to demonstrate that a legitimate government interest was advanced by the prohibition, and said no evidence supported the notion that so limiting the content on the display had "anything to do with highway safety or aesthetics."

It is a testament to the safety of EMCs that, since 1979, the Federal Highway Administration has not seen any need to revise its recognition of the legality of on-premise commercial variable electronic message signage, provided that:

1. the displays are changed at reasonable intervals,

2. the signage does not violate the compliance agreement's definition of flashing lights, and

3. a state has accepted local controls in lieu of state controls and such signs are considered to have been in customary use within the locality, or a state court has determined that such signs do not constitute flashing, intermittent or moving lights.

Continue to:

• Features and Advantages of EMCs
• An Answer to the Challenge of Changing Demographics
• Frequently Asked Questions about EMCs