Idaho stop

The Idaho stop is the common name for laws that allow bicyclists to treat a stop sign as a yield sign, and a red light as a stop sign. It first became law in Idaho in 1982, but was not adopted elsewhere until Delaware adopted a limited stop-as-yield law, the "Delaware Yield", in 2017. Arkansas was the second US state to legalize both stop-as-yield and red-light-as-stop in April 2019. Studies in Delaware and Idaho have shown significant decreases in crashes at stop-controlled intersections. In France and Belgium, some intersections use red-light-as-yield signs.

These exceptions for bicyclists respond to the fact that traffic light sensors may not recognize cyclists. Similar laws also encourage riders to take safer low-traffic streets instead of faster high-traffic roads.

The original Idaho yield law was introduced as Idaho HB 541 during a comprehensive revision of Idaho traffic laws in 1982. At the time, minor traffic offenses were criminal offenses and there was a desire to downgrade many of these to "civil public offenses" to free up docket time.

Carl Bianchi, then the Administrative Director of the courts in Idaho, saw an opportunity to attach a modernization of the bicycle law onto the larger revision of the traffic code. He drafted a new bicycle code that would more closely conform with the Uniform Vehicle Code, and included new provisions allowing bicyclists to take the lane, or to merge left, when appropriate. Addressing the concerns of the state's magistrates, who were concerned that "technical violations" of traffic control device laws by bicyclists were cluttering the court, the draft also contained a provision that allowed bicyclists to treat a stop sign as a yield sign—the so-called "rolling stop law". The new bicycle law passed in 1982, despite objections among some bicyclists and law enforcement officers.

In 2006, the law was modified to specify that bicyclists must stop at red lights and yield before proceeding straight through the intersection, and before turning left at an intersection. This had been the original intent, but Idaho law enforcement officials wanted it specified. The law originally passed with an education provision, but that was removed in 1988 because "youthful riders quickly adapted to the new system and had more respect for a law that legalized actual riding behavior".

In 2001, UC Berkeley physics professor Joel Fajans and magazine editor Melanie Curry published an essay entitled "Why Bicyclists Hate Stop Signs" on why rolling stops were better for bicyclists, generating greater interest in the Idaho law.

The first effort to enact the law outside of Idaho began in Oregon in 2003, when the Idaho law still only applied to stop signs. While a bill overwhelmingly passed in the House, it never made it out of the Senate Rules Committee. The Oregon effort in turn inspired an investigation of the law by the San Francisco Bay Area Metropolitan Transportation Commission in 2008. That investigation failed to spawn legislation, but did garner national attention, leading to similar efforts nationwide.

The term "Idaho Stop" came into popular use as a result of the California effort in 2008. Prior to that, it had been called "Idaho Style" or "Roll-and-go". "Idaho Stop" was popularized by bicycle blogger Richard Masoner in June 2008 coverage of the San Francisco proposal, but in reference to the "Idaho Stop Law"; the term had been used in discussion since at least the year prior. In August of the same year, the term—now in quotes—first showed up in print in a Christian Science Monitor article by Ben Arnoldy who referred to the "so-called 'Idaho stop' rule". Soon after, the term "Idaho stop" was commonly being used as a noun, not a modifier.