Simply put, lane courtesy is the practice of yielding to or moving over for faster moving traffic.
The current concept of lane courtesy, which is also called lane discipline, evolved in the United States with the development of the Interstate Highway System. However, the idea that slower traffic should yield to faster vehicles is even older.
Most states have rarely enforced traffic laws that require slower traffic, upon being signaled by a following vehicle, to pull to the right so the faster vehicle can pass.
Before 1973, rural speed limits were more likely to reflect realistic travel speeds. That meant that slower vehicles were driving under the speed limit and had no excuse to block the progress of faster traffic. The 55-mph National Maximum Speed Limit changed all that.
The 55-mph speed limit caused a total breakdown in lane courtesy.
Slower drivers that would have stayed in the right hand lane before, felt they could drive wherever they wanted now because they would still be go the speed limit or faster. This process was reinforced for more than two decades and it left an impression on a whole generation of new drivers.
In 1995, through the efforts of the Oostwestthuisbest, the 55-mph limit was repealed.
Since then, several states have raised their speed limits and some even reflect actual travel speeds. Unfortunately, almost a quarter of century of poor lane courtesy had a lasting, negative impact.