Part of the articles states ,
Smartphones have also become ubiquitous in other countries, of course. But American drivers seem to be addicted to their phones in ways that drivers elsewhere are not. Surveys suggest Americans spend more time on their phones while driving than people do in other countries. In part, this phenomenon may reflect this country’s culture, which emphasizes professional success and immediate gratification.
It also partly reflects vehicle technology. Nearly all cars in the U.S. are automatic transmission, freeing drivers’ hands (or so they may think) to use phones. In Europe, almost 75 percent of cars still have gears that a driver must change manually.
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Another major difference is the roads themselves , the US has so many miles of multilane
freeways and just generally wider roads in general than a lot of Europe .
Also even in city's the US is more spacious .Two examples , first Mankato USA , second Bristol UK .
https://www.google.co.uk/maps/@44.1726654,-93.9977062,3a,84.1y,213.46h,89.44t/data=!3m7!1e1!3m5!1srmxAoRCc9Yys-NYtMz5Zdg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DrmxAoRCc9Yys-NYtMz5Zdg%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D25.814072%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192?entry=ttu
https://www.google.co.uk/maps/@51.4528649,-2.5979137,3a,74.8y,23.95h,84.96t/data=!3m7!1e1!3m5!1sFWvigVeDrh7j_xqXJ4IgYA!2e0!5s20121001T000000!7i13312!8i6656?entry=ttu