Allstate has declared that residents of three Massachusetts’ cities rank among the worst drivers in the country in its annual Best Drivers Report. But before you decide to avoid the roads of Boston forever, consider that there are certain limitations to the Allstate survey. As Slate's Explainer discussed last year, Allstate’s methodology doesn't consider the miles covered or vehicular mayhem, i.e. drunk driving. (Of course, we also noted that Allstate insured only 10 percent of Americans, none of whom were in Massachusetts. It would appear—perhaps unfortunately for Allstate—that they are now.)
In light of the new survey, we are reprinting our original story below.
Imagine: You’re driving a car, and the driver ahead of you is behaving erratically. He can’t stay in a lane. He puts on his left turn signal but doesn’t turn. He slows to a near stop for no apparent reason, then surges forward. Finally, he makes a right turn from the left lane. You mutter to yourself, “This city has the worst [expletive] drivers.”
What city are you envisioning?
Everyone who has ever set foot on an accelerator thinks they know where the worst drivers live, but they can’t all be right. I set out to determine which city’s drivers most deserve our steering-wheel slamming, bird-flipping frustration.
First, a caveat. There hasn’t yet been a convincing ranking of cities with the worst drivers, because reliable data is hard to come by. There’s no clearinghouse for statistics on bad driving based on uniform methodology for every city. This effort will involve compromises and educated guesses, along with a healthy dose of personal opinion.
Our first stop is the annual “America’s Best Drivers Report,” published by Allstate Insurance Company. Allstate uses claims data to determine how often drivers in the largest 200 U.S. cities get into accidents. The report is meant to celebrate the cities with the fewest crashes, but reporters get far more joy flipping the table upside down to find out which cities fared the worst. In 2012, the unofficial “worst drivers” title went to Washington, D.C., followed by Baltimore, Providence, R.I., Hialeah, Fla., and Glendale, Calif.
The report has several limitations. Allstate insures only about 10 percent of U.S. drivers and doesn’t cover anyone in Massachusetts. (In informal surveys, Bostonians are leading candidates for worst-driver honors.) Insurance claims are also only one indicator of inferior driving. The Allstate report doesn’t consider fatalities, drunk driving, or other forms of vehicular mayhem. Finally, the survey fails to take into account the number of miles that each insured driver covers in a year. Less mileage means fewer accidents, even if you’re a terrible driver.
Still, the Allstate report is both a useful indicator and a good way to winnow down the candidates. We can safely assume that the city with the worst drivers is somewhere in Allstate’s bottom 50. Phoenix, Indianapolis, and Denver, therefore, are off the hook, along with a raft of others. One notable escapee is San Diego, the city with the most drunk driving arrests. Let’s also ignore cities with populations below 150,000, because data on those places is limited. Plus, few people have ever said, “Hayward, California has the worst drivers!” We’ll add Boston back into the mix, based on opinion surveys. (You’re not getting off that easy, Boston.) That leaves 39 candidates.
The first task is to consider mileage. The Center for Neighborhood Technology’s Housing and Transportation Affordability Index estimates the number of miles that members of an average household travel by car in a year, broken down by city. Among our candidates, the average is 14,433 miles. (Garland, Tex., tops our list at 19,234 miles, while New York City is at the bottom with 9,375). We’ll incorporate this information into the data by creating a multiplier based on how many miles a city’s residents drive relative to the average. The Allstate rankings, for example, are based on the number of years between accidents. San Franciscans average 6.5 years between crashes, but they drive 74 percent as many miles as the average for cities in our survey, so we lower their years-between-accidents to 4.8 to account for how rarely they drive.
Adjusting the Allstate rankings for mileage this way has significant effects. Washington, D.C. remains the worst driving city using the insurance claims data, but Philadelphia surges to second worst. Hialeah drops seven places, from fourth to 11th.
Next we consider additional indicators. Car crashes are bad, but some accidents are worse than others. In July 2012, the Centers for Disease Control and Prevention published automobile fatality data for major cities and metropolitan statistical areas from the year 2009. It’s useful for our purposes, but it comes with a couple of caveats. The researchers didn’t publish data for some of the smaller cities on our list. In those cases, we’ll use data from the larger metropolitan area. In addition, three cities (Boston, Newark, N.J., and Providence) had fewer than 20 fatalities, but the precise number is unpublished. We’ll assume that each of these cities had 10 fatalities, so we have a number to enter into the calculations.