THE HUMAN ELEMENT
Much is said about the incompetence of typical drivers. Although they are butt of many jokes and can be a pain-in-the-neck to fellow motorists, how much of this negative perception is justified? How competent are typical drivers in managing their automobiles and how good are they at choosing safe driving speeds?
SPEED LIMITS AND FATALITY RATES
The following chart shows the relationship between the fatality rate and speed limits in the state of Utah. Except for numerical values, this chart is representative of conditions in virtually all other states.
Normal Speed of Traffic has Increased by Approximately 0.34mph per Year
The following conclusions are indicated by the chart.
- Contrary to expectations, when the 55mph national speed limit was imposed, the fatality rate unexpectedly increased after an initial decline and did not return to the original level for approximately five years.
- Except for erratic behavior during the years immediately following 1974, the fatality rate declined 74% from 3.42 to 0.9 deaths per hundred million miles between 1974 and 2012.
- On Utah freeways, the 85th percentile speed increased from approximately 70mph in 1975 to 82mph in 2012, which is 0.34mph per year.
- There appears to be no direct relationship between changes in freeway speed limits and fatality rates. When speed limits were increased by 10mph in 1986 and 1995, the fatality rate continued to fall.
MODERN TECHNOLOGY ALLOWS MOTORISTS TO DRIVE SAFELY AT HIGHER SPEEDS
Improvements in highways and automobiles have allowed motorists to travel safely at ever faster speeds. Although speeds have increased by approximately 17% the fatality rate has declined by 74%. For those who remember driving on the highways of the 70's, the improvement is striking.
Although drivers make mistakes the data indicates that they are generally very capable of making good decisions and driving safely. Enforcement agencies are obligated to design and implement fair enforcement policies and avoid unfair practices that abuse the driving public.
The next page presents the requirements for producing fair, enforceable speed limits.