Time-saving bias
Time-saving bias is misjudging how much time you save by going faster. People overestimate the time saved when speeding up from an already high speed and underestimate it when speeding up from a low speed.
In everyday life
A commuter shrugs off a route change that would raise their average speed from 20 to 40 km/h through town, though doubling the speed would cut the trip time in half.
Running late, you weave through highway traffic well above the limit on a short stretch, sure you are gaining a lot, and arrive barely a minute or two sooner than if you had driven calmly.
Why your mind does this
Imagining the past and the future is hard, so the brain uses the present as a template. Assuming things will stay roughly as they are now is a quick and usually workable guide. Making sense of events after the fact also helps us learn lessons and feel in control.
Its family, in 30 seconds: Projecting ourselves
How to spot it
Ask how many minutes you would really gain, using the simple math of distance divided by speed.
How to counter it
Work out the actual trip time at each speed before taking risks to go faster.
Same family: Projecting ourselves
SourcesSvenson (2008)·Wikipedia