But the number of drivers who texted at the wheel had risen from 4% in 2011 to 5% in 2012. Those driving in inappropriate footwear, such as flip-flops, remained constant at 12%.
Some 3% admitted driving without a seatbelt in the 2012 survey, compared with 5% in 2011, while those admitting tailgating had fallen from 5% last year to 4% this year.
Eating and drinking at the wheel appeared the most common bad driving habit, with 27% admitting to it.
As many as 3% of women said they did their make-up while driving, while 2% opened up to driving without their glasses or contact lenses.
Sainsbury's Car Insurance head Ben Tyte said: "It's encouraging to see that driver behaviour on our roads remains, on the whole, at a consistent level and is improving in some areas. We're pleased to see a reduction in excessive speeding, as this is the cause of so many accidents on our roads."