Paceometer

It is a truth universally acknowledged that the faster you travel, the quicker you will get to your destination, but not necessarily as quickly as you imagine, according to an article in the Mrch 2013 edition of Judgment and Decision Making. They report studies which show that drivers made erroneous estimations of how much time they would save if they increased their speed, overestimating the time if they increased from a relatively high speed and underestimating when increasing from a lower speed. Respondents often thought that increasing the mean speed from 70 to 110 kph would save more time than an increase from 30 to 40, although the latter actually saves more time.

This time-saving bias, they argue, is down to people’s failure to recognize that the relationship between speed and time saved is not linear but curvilinear and this bias could be reduced by converting speed information into a more intuitive measure of pace such as the time required to cover a fixed distance. Hence the paceometer illustrated above.

The black digits show speed in the conventional way – miles per hour – while the blue numbers show how many minutes it takes to travel ten miles. A close inspection reveals that the relationship between the two is non linear and that the faster you are going, the less time you will save by driving even faster. Drive at thirty miles per hour instead of 20 and you will shave ten minutes for every ten miles driven, whereas going at 80mph instead of 70 saves “under a minute”.

One to think about when you are behind the wheel.