Freeway Speed, from James Sogi
On a recent trip from Mt. Baker to Seattle driving on I5 I noticed that driving about 1 or 2 miles an hour slower than prevailing traffic made driving a LOT easier. First I could drive at the same speed without having to make any adjustments to speed and avoided changing lanes. All the people passing had to made serial adjustments and multiple lane changes. This eased the stress of driving and reduced the number of decisions and risk. Over several hundred miles the difference in arrival time was just minutes difference. It reminded me of Triumph of the Optimists leverage study when 1.9x was optimal, but 2x went bust during the last century.