FHWA administrators want to stop humorous traffic safety messages
Photo 186639703 © Darwin Brandis | Dreamstime.com


FHWA administrators want to stop humorous traffic safety messages

Researchers are still trying to evaluate the effectiveness of direct message signs on highways.

Across the country, Federal Highway Administration (FHWA) division administrators, the liaisons between FHWA and state transportation departments (DOTs), are cracking down on state DOTs for serious violations—posting humorous messages on their digital highway message signs.

According to The Washington Post, the New Jersey Department of Transportation irritated FHWA Division Administrator Robert J. Clark with traffic board messages such as, “We’ll be blunt/Don’t drive high” and “Hold on to your Butts/Help prevent Forest Fires.”

Clark sent a cease and desist letter to New Jersey DOT claiming that using highway signs for such messages does not “promote the safe and efficient use of the roadway, does not serve a highway purpose, is inconsistent with both law and regulations, and increases the liability risk to the owner of the roadway facility.” 

In dropping the hammer, Clark relied on a revised section of the 2009 Manual on Uniform Traffic Control Devices that reads, “Messages with obscure or secondary meanings, such as those with popular culture references, unconventional sign legend syntax, or that are intended to be humorous, should not be used.”

Federal bureaucrats are not exactly known for their sense of humor, but it is worth noting that highway safety is one area in which New Jersey DOT excels. In Reason Foundation’s Annual Highway Report, New Jersey routinely ranks in the best 10 states for having the lowest fatality rates. The state most recently ranked 4th in overall highway fatality rate, 9th in rural highway fatality rate, and 18th in urban highway fatality rate. New Jersey ranks much worse in categories such as the efficiency of highway spending, quality of pavement conditions, and traffic congestion delays. Perhaps Mr. Clark should worry more about the conditions of highways. 

And New Jersey is not the only state to be threatened. According to the Post and Governor’s Highway Safety Association, some states were warned they could lose federal funding if they continued including humorous messages. 

Yet the federal rule on ‘appropriate’ signs seems to be enforced haphazardly. Tennessee used, “Ain’t nobody got time for a wreck, slow it down.”

Pennsylvania’s recent holiday message was, “Only Rudolph should drive lit/Plan a sober ride.”

Virginia has used, “This isn’t NASCAR, slow down.”

And Mississippi displayed, “Texting and driving? I’m the problem it’s me.”

None of the state highway administrators complained about these messages. Apparently, being lit, NASCAR racing and Taylor Swift lyrics are fine to reference on digital highway signs, but holding on to your butts is not.

The most critical question for drivers and highway officials is straightforward: Do highway safety messages on digital highway signs improve safety?

With relatively limited data, the answer is not clear. Trip Shealy, a Virginia Tech transportation engineering professor, studied how the public responded to such messages and concluded that drivers believed they were effective and were not concerned with their appropriateness.

Shealy’s researchers hooked 300 participants to brain monitors and found that messages using humor or wordplay triggered more brain activity. Put another way, humorous messages are more likely to reach the intended audience. The study found:

The results indicate people perceive all types of non-traditional safety messages as effective. Messages about distracted driving and driving without a seat belt, messages meant to provoke a negative emotion, and messages using statistics are perceived to most likely change driver behavior.

However, a Transportation Research Record study, “Does Displaying Safety Messages on Dynamic Message Signs have Measurable Impacts on Crash Risk?” found that while there were marginal decreases in nighttime crash activity and speeding in places with the messages, neither finding was statistically significant.

A Science magazine study found that when Texas motorists were shown the number of fatalities in the area, the number of crashes actually increased slightly:

Contrary to policymakers’ expectations, we found that displaying fatality messages increases the number of traffic crashes. Campaign weeks realize a 1.52% increase in crashes within 5 km of DMSs [dynamic message signs], slightly diminishing to a 1.35% increase over the 10 km after DMSs.

An Old Dominion University study found:

Results indicate that multi-page messages increased crashes by 1.5% in 2019, and reduced vehicle speed around DMS by 2-4%, relative to single-page messages. Although DMS can provide valuable, actionable information to drivers, DOTs should be more selective in the timing and formatting of messages as to not impose additional externalities on drivers.

A separate panel by the Transportation Research Board indicated that message signs should be simple and not humorous. But the study’s 120-person sample size was much smaller, and it did not find any evidence that humorous signs were bad, but rather “appropriate signs” fit more with transportation departments’ missions.

“Appropriate” can probably be replaced with “boring.” Yet, boring messages do not seem to reduce fatalities, considering the U.S. traffic fatality rate has been on an uphill climb for most of the past decade. 

The best example of the importance of capturing the audience’s attention may be in aviation, which is dramatically different than highway safety but offers some lessons. Southwest Airlines has always used humor in its safety videos. Delta Air Lines did as well during the 2010s. On one flight I was on, the flight attendant directed passengers to place the mask on their child with the greatest earnings potential first, and then help others. I looked around, and almost every passenger was paying attention to the flight attendant. In contrast, Delta’s current sanitized safety videos are ignored by 75% of passengers. A 2015 article in the journal Safety Science found that recall of safety messages improved with humorous briefings. Safety incidents on planes are extremely rare, and airline passengers are different than drivers, but I would much rather be on a plane with passengers who know what to do in an emergency, even if they are making calculations about their child’s future earnings.

On roads, we cannot conclusively say that dynamic message signs improve safety. But we also cannot say that they make safety worse. Highways are owned by the states, not the federal government, and there needs to be overwhelming evidence for FHWA to threaten to pull, let alone justify pulling, a state’s highway funding.

State transportation departments should be able to experiment to find what works best for their highways and drivers.