Q: There is a commercial on TV featuring a deaf driver. Are deaf people allowed to drive, or are they restricted because of their hearing loss?

A: Perhaps you saw the car commercial featuring Kris Martin, a six-time National Kart Champion, NASCAR, and Le Mans professional race car driver who is deaf. If so, I hope you found him as inspirational as I did. But being an inspiration isn’t one of the qualifications for a driver’s license. That’s OK for Kris though, and for many other deaf people, because being deaf isn’t a disqualifier.

Back in 1920, there were a few states that, for a short time, didn’t allow deaf people to get a driver license. Apart from those states during that time, deafness has not disqualified people from becoming licensed drivers. That hasn’t been the case for commercial vehicle drivers though. Up until 2006, a package delivery company had a policy of not employing deaf workers as drivers. The company said that deaf drivers posed a safety problem because of their inability to hear other vehicles, but a federal appeals court determined that there wasn’t evidence to back up that assertion.

So how risky is it? Either hearing loss is a significant risk factor for driving and should prevent or limit people from driving, or it’s not a risk factor and deaf drivers shouldn’t face any additional hurdles to getting a license. The problem is that we don’t have great data to support either position (although, based on what I’ve read, it leans in favor of deaf drivers).

According to the shipping company I mentioned earlier, deaf drivers are a threat to our roads. In contrast, the World Federation of the Deaf, in their statement on deaf people’s right to drive, said, “It is a well-known fact; deaf drivers have been involved in car accidents less than the average driver.”

Unfortunately, neither group provided any data to support their position.

It seems like the last time researchers got excited about this topic was over half a century ago. I came across four studies from the 1960s. One concluded that deaf drivers were safer than hearing drivers, one concluded that deaf and hearing female drivers performed similarly but deaf male drivers crashed more frequently, and the other two studies (actually all four studies) had too many flaws to be conclusive.

More recently, a 2010 study found that deaf adults see better than hearing people, suggesting that their increased peripheral vision serves as a protective factor when driving. Oh, there was a “fascinating new study” concluding that deaf drivers could be the world’s safest motorists,” but the only source I could find was the Weekly World News. (It bills itself as the world’s only reliable news, but this week’s headlines include dinosaurs on Mars and a toilet that’s also a space-time portal.)

I’m not a data expert, but if multiple studies can’t confirm that there’s a problem, maybe there’s not a problem. In contrast, if you wanted to highlight a demographic that’s legally allowed to drive despite how dangerous they are, that would be young drivers. Last year drivers aged 16-25 were involved in 32 percent of fatal crashes in Washington, but they make up less than 15 percent of licensed drivers.

Consider also the risks that some drivers choose to take, such as driving impaired, speeding, or allowing distractions to interfere with their driving. Hearing loss and deafness can cause a driver to miss out on some useful information in their surroundings, but our decisions as we drive are the biggest factor in making it home safely.

Doug Dahl writes a weekly traffic column for this newspaper. He is with the state Traffic Safety Commission.