brainwagon "There is much pleasure in useless knowledge." — Bertrand Russell


Is mobile operation of a ham radio really safe?

The federal government is currently considering the possibility of legislation banning the use of cell phones and texting. I'm mostly okay with that, because, quite frankly, it's obvious that people aren't very good at operating a cell phone or texting while driving, a fact which has been reinforced by study after study. But while many radio amateurs accept this conclusion with respect to cell phones, radio amateurs as a whole seem to think that it doesn't apply to operation of an amateur radio transmitter while the vehicle is in motion. Witness the quotation from ARRL CEO David Sumner:

According to ARRL Chief Executive Officer David Sumner, K1ZZ, it boils down to the difference between simplex -- when only one message can be sent in either direction at one time -- and duplex -- a communications mode, such as a telephone system, that provides simultaneous transmission and reception in both directions. Harrison, citing Sumner's 40-plus years of experience as an Amateur Radio operator, puts it this way: "Simplex, two-way radio operation is simply different than duplex, cell phone use. Two-way radio operation in moving vehicles has been going on for decades without highway safety being an issue. The fact that cell phones have come along does not change that."

via ARRLWeb: ARRL NEWS: ARRL President Presents League's Views on Distracted Driving Laws to Safety Advocacy Group.

But here's the thing that bothers me. This is just a bold assertion: that operation of simplex radios is inherently safer than duplex radios. Here is what the NSC President Janet Froetscher had to say about the subject:

The NSC position is grounded in science. There is significant evidence that talking on cell phones while driving poses crash risk four times that of other drivers. We are especially concerned with cell phone use because more than 100 million people engage in this behavior, with many doing so for long periods of time each day. This exposes these 100 million people and everyone who shares the road with them to this increased crash risk every day. This combination of risk and exposure underlies our specific focus on cell phones.

We are not aware of evidence that using amateur radios while driving has significant crash risks. We also have no evidence that using two-way radios while driving poses significant crash risks. Until such time as compelling, peer-reviewed scientific research is presented that denotes significant risks associated with the use of amateur radios, two-way radios, or other communication devices, the NSC does not support legislative bans or prohibition on their use.

That is not to say that there is no risk associated with drivers using amateur or two-way radios. Best safety practice is to have one's full attention on their driving, their hands on the wheel and their eyes on the road. Drivers who engage in any activity that impairs any of these constitutes an increased risk. While the specific risk of radio use while driving is unmeasured and likely does not approach that of cell phones, there indeed is some elevated risk to the drivers, their passengers and the public associated with 650,000 amateur radio operators who may not, at one time or another, not concentrate fully on their driving.

This is widely being circulated as vindication of the idea that operation of a ham radio while simultaneously operating a motor vehicle is safe. Unfortunately, I don't think that is an accurate representation of Froetscher's position. Froetscher merely said that she was unaware of any scientific, peer reviewed studies that demonstrated a significant safety risk. As we should all know, absence of evidence is not evidence of absence. David Sumner's assertion that simplex is inherently safer than duplex is just that: an assertion, and is not evidence.

The fact is that humans are very bad at evaluating risks and their own performances at tasks. That's why we have scientific studies like the ones that we have for operating cell phones. Because there are 100 million cell phones being used literally every day, there is plenty of data to sift through on their potential role in accidents. Even so, it's taken about a decade for the true extent of the risks involved in cell phone operation to become documented.

There are only about 660,000 or so hams licensed in the U.S. The vast majority of these do not operate mobile. The vast majority of those do probably spend most of their time listening. In such a case, we'd expect that the number of accidents caused to be much lower than those caused by cell phones, even if mobile operation was every bit as dangerous as using a cell phone. The overall instance of accidents may be only 0.1% or less of the levels we see from cell phones. One study estimated that 6000 accidents might have been caused by cell phones in California in 2001. Even if ham radio were as dangerous, we might expect to see only six accidents in the entire year from ham radio operation.

I'm not saying that we should outlaw mobile ham radio operation. Without evidence that it is dangerous, I think it is premature to make it illegal. But I also think that it is inappropriate to confidently assert that we understand what the risks are, and that we actually present no significant risk to ourselves or to others on the road.

Addendum: Ben makes an additional point which I think is worthy of mention. The ARRL is in part justifying their opposition to bans on mobile radio by suggesting that amateur radio serves a vital purpose in supporting emergency communications. I think this is a somewhat odd claim to make, since it should be fairly obvious that the overwhelming majority of emergencies are reported by calling 911 on the cell phone. Many states have exemptions for mobile cell phone use in times of emergencies: you can report an accident while calling 911 while your car is in motion. The ARRL could choose to suggest to its members that only emergency communications be carried out while the car is in motion, but instead, they suggest that the possibility of using a mobile radio to report an emergency justifies their free use for routine communications while the vehicle is in motion. I agree with Ben, I don't think this is a reasonable "best practice" suggestion.

One slightly convincing argument that I haven't heard, but which I can imagine someone making is that without the incentive of being allowed mobile operation, radio amateurs won't install mobiles in their vehicles, and therefore we lose a valuable resource for reporting accidents and dealing with emergencies. This is an argument which I might seriously consider, and could be made compelling with the right sort of quantifiable evidence to determine the tradeoffs of different regulatory strategies.