The gadget that could make you a better driver.

The gadget that could make you a better driver.

How we get from here to there.
Nov. 30 2009 12:32 PM

It Knows If You've Been Speeding

Can a device that tracks when I swerve, accelerate, and brake make me a better driver?

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The reports came a few weeks later. Among the variables tracked by the ROVER are hard braking, rapid acceleration, overspeed, nighttime driving (as the report noted, "fatigue, poor lighting and the possibility of other drivers being impaired may place you at much higher risk when driving at night"), mpg, and idling. In the first report, I was pleased to see I had no hard braking and no rapid acceleration, though I did have 22 minutes of idling and an average of 1.1 overspeed events per hour. I had actually thought this would be higher, as I was definitely exceeding 55 on certain marked sections of I-95—as was everyone else—but it turns out ROVER doesn't, for the moment at least, track speed in relation to actual posted speeds; in part, Armitage told me, because speed limit data are so spotty. By the next week I had pulled something of a minor miracle, at least for Cartasite: a perfect 100 score. Over 7:39 hours and 217.92 miles of driving, I had no hard braking events, no rapid acceleration, a mere four minutes of idling (the device begins recording idling events after three minutes), and no nighttime driving.

I am, admittedly, a bit of an outlier when it comes to this sort of thing; having received my perfect score, it occurred to me that I should have placed another device in, say, a New York City taxi. But thanks to reports Cartasite shared with me (names omitted), you can get a sense of how steep the curve is: One driver, who notched a score of 72, clocked more than 30 hard braking events per hour and half as many rapid acceleration moments (Armitage suspects the driver may have been on a cell phone). In one fleet vehicle report that came in, the driver was reported to have been idling for seven hours—even though he had driven only 11 miles that day.


As with "smart metering" systems for domestic electricity use, the idea here is that feedback—by giving people a sense of what other people's behavior is, or what the ideal behavior should be—can make people's behavior change. Idling is a perfect example: Since the costs are essentially invisible (particularly for company drivers) and the behavior seemingly innocuous, there's little incentive to stop. (People also misunderstand when it makes sense to idle: Studies have shown that drivers falsely believe idling is more efficient than stopping and starting the engine for pauses up to three minutes long, when it's reality only more efficient to idle for less than a minute.) But as Michael P. Vandenberg and Anne Steinemann have argued, the societal consequence of mass idling—while small in the context of overall driving—is still huge: "[I]f Americans could be induced to idle for only thirty seconds from a cold start and ten seconds while waiting, 12.8 billion pounds of carbon dioxide emissions could be eliminated per year. This behavior change also would generate savings of roughly 640 million gallons of gas." Put another way, Americans simply sitting in their car produce more emissions than the sum total emissions (including nondriving activities) of countries like Costa Rica.

Better feedback could help us curtail driving behaviors that are linked to both increased emissions and the likelihood of crashes. Things like hard braking and speeding consume more fuel—an Australian study found that larger cars driven conservatively can get superior fuel efficiency than small cars driven aggressively—and they also seem to be predictive of crash involvement. As that same study noted in relation to fleet vehicles, "the case study found that the fuel consumption rate of crash-involved vehicles was higher than that of vehicles not involved in crashes." The things that make for efficient driving—lessening unnecessary braking by anticipating future events, avoiding higher speeds, etc.—are the things that make for good driving in general.

How effective can driving feedback be? The yearlong trial program in Denver called "Driving Change" (which employed ROVERs) recorded a 35 percent reduction in drivers' total idling time. A study involving a trial group of teenage drivers in the United Kingdom, using an in-vehicle data recorder from another company, GreenRoad, found, according to New Scientist, that "the number of unsafe driving events undertaken by each driver halved after the warning lights were turned on." The simple presence of a device seems to change driver behavior without any further intervention (one study found the device reduced crashes by 20 percent). Insurance companies, not surprisingly, have been experimenting with IVDRs—for those data would surely be more predictive of risk than the crude measures currently employed—although for now they have largely been used to measure only basic things like mileage. The question is: Would the average driver accept having her behavior monitored if the promise was lower insurance premiums? For now, the IVDR action is hottest in situations in which the driver is not driving his own car: livery drivers (whose bosses are looking to reduce fuel costs and liability claims) and teens. DriveCam, for example, sells its in-vehicle monitoring technology (which includes video snippets of unusual events) to parents of teen drivers. (American Family insurance customers can get it for free).

A number of other questions still remain: Is it more effective to give drivers real-time or retrospective feedback? How do you present that feedback? Do you need to provide positive, as well as negative, feedback? Will feedback without further incentives (or disincentives) do any good? In any case, it's clear that driving doesn't always allow for the "better angels of our nature," and the road to greater self-awareness—and safer driving—may run through your vehicle's onboard computer.

Tom Vanderbilt is author of Traffic: Why We Drive the Way We Do, now available in paperback. He is contributing editor to Artforum, Print, and I.D.; contributing writer to Design Observer; and has written for many publications, including Wired, the Wilson Quarterly, the New York Times Magazine, and the London Review of Books. He blogs at and lives in Brooklyn, N.Y. You can follow him on Twitter at

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