GO WHEN IT’S CLEAR, STOP WHEN IT’S DANGEROUS: Why Bikes Should Treat Red Lights and Stop Signs as Yields

San Francisco is contemplating an “Idaho Stop” rule allowing bicyclists to treat red lights like stop signs and stop signs as if they were yields.  Should Boston do it too?


 “You know why I pulled you over,” the cop said.  It was a statement, not a question.

 I didn’t want to come across as obnoxious, but the situation was so obvious that I couldn’t help laughing as I got off the bike and took off my helmet.   I had come to the intersection, slowed, looked both ways and, seeing no cars, continued through.  I do it all the time.

 “Of course; I went through the red light,” I said. “Which I did in order to be safe.  There were no cars coming, and I wanted to get through before any did arrive.  It’s a busy street and it’s a lot safer to cross when there are no cars.”

“You went through the light,” he said, starting to fill out the ticket.  I could see that it was a $20 fine.

“Yes,” I said.  “I’d be willing to pay $20 pretty often in order to not risk my life.”

He looked up at that.  “It’s dangerous to run the light.” 

“Not if there are no cars coming.  It’s more dangerous to go on the green if there are cars turning or racing through. ”

“That makes no sense.”  At least he was listening.

“About a half-dozen cyclists have been killed over the past few years by cars, or trucks, or buses.  None of them were running a red light.  In fact, several of them were going straight towards a green light when they got hit.  If there are lots of fast cars coming up behind me potentially going to turn I won’t go through an intersection even if I have a green light.  What matters is the amount of traffic and their speed -- it's the danger, not the color of the light.  If there are no cars it’s safer, no matter if it’s red or green.”

“I’ve never heard anything like that.  I ride a bike.  You broke the law.”

“Look, I’ll take the ticket.  But I’d rather break the law than die.  And you should think about what would make you safest the next time you go out for a ride.”

I didn’t add that if I do stop for a red light and the intersection has a “Leading Pedestrian Indicator” that gives walkers a 3-second head start, I start pedaling when the Walk signal lights even though the light is still red.  Or that I also go with the Walk signal at 4-way-red intersections at busy crossroads where all traffic is stopped so pedestrians – who I make sure to give priority to – can move catty-corner as well as straight across.

So the cop wrote the ticket.  I rode off.  And I paid.  And I’d be happy to pay again.  It’s cheaper than hospital bills.


In 1982 the Idaho state courts were getting clogged with minor traffic violations which the law treated as criminal offenses, including many “technical violations” of traffic signal regulations by cyclists such as the requirement for full feet-on-the-ground stops at stop signs.  The state magistrates pushed to turn many of the traffic violations into “civil public offenses” that didn’t require court appearances.  In the process, a senior court administrator saw an opportunity to also update the state’s bicycling regulation.  He appended a change to allow bicyclists to treat red lights as stop signs and stop signs as yield signs.  Cyclists can also treat a red light as a yield if they are turning right, continuing slowly if no one is coming .    In the year following the new laws passage “bicycle injury rates declined by 14.5 percent and there was no change in the number of bicycle fatalities” and there is “no evidence” since then “of a long-term increase in injury or fatality rates as a result of the adoption of the “Idaho stop” law.”

In the years since then, the inability of first-generation buried traffic-control sensors to pick up the presence of a bicycle has led a number of states to allow cyclists to proceed through a red light after a passage of time that the signal doesn’t change.

Critics charge that the “Idaho stop” simply panders to the ill behavior of bicyclists and their self-entitled demand for special treatment.  Supporters point out that bikes aren’t the functional equivalent of cars and are often appropriately and legally treated differently.  If anyone is being given special treatment it’s car drivers whose multi-ton weapons are the real source of danger on the roads.  And while there obviously are rude, stupid, and self-endangering cyclists there is just as high a percentage – if not more – rude, stupid, and dangerous-to-others car drivers.  Not to mention all the pedestrians who step into the road with their eyes glued to their phones. The point is that every category of humans has its percentage of jerks.

Making the situation more complicated is the frequent dysfunctional timing of walk signals in many cities, leading pedestrians to cut across the street when it feels safe to do so rather than when the “walk” signal or green light is on.  It would make no more sense to send the police out to give these reasonably-acting people jaywalking tickets than it does to start ticketing cyclists for going through empty intersections.

The Idaho law doesn’t allow, and no one suggests, that bikes should be able to race through a busy intersection or take a left turn if cars are coming.  If there's already a car or another bike – or a pedestrian – in the intersection they have the right of way.  But if there is no one there, muscle momentum should rule – the bikes should roll.


Most multi-person activities – in the workplace, on elevators, on the sidewalk, and on the roads only work because everyone using them goes beyond the formal rules to decide when to go, when to slow, and how to weave through problems.  No matter how formalized or rule-directed, they all depend on the problem-solving creativity and self-direct initiative of the people actually there. Including bicyclists. 

Recently, a San Francisco police captain announced that his district would begin enforcing the city’s full-stop-at-stop-sign law for bicyclists.  An unofficial group of cyclists then announced that they would demonstrate what would happen to traffic if they actually followed the rule.  The result, focused on one intersection in the “Wiggle” section of a key cross-town route was total congestion.  (see the video).  As soon as this “tactical urbanism” event started the cars started stacking up behind them.  As each individual cyclists came to the corner, stopped, waited until there was absolutely no cars coming across, and then slowly moved the line of waiting cars grew longer. 

Point made.  San Francisco is now about to pass an “Idaho Stop” law.


The purpose of traffic signals is to keep things flowing and improve safety.  Treating bicycles as if they are cars or trucks or buses makes no sense, both functionally and for the purpose of keeping people safe.

It is probably politically impossible to get the laws changed in Massachusetts today.  But the reality is that most bicyclists act as if the “Idaho Stop” was already law – not because they are criminals but because doing so makes their ride safer and keeps traffic moving.  Someday we should bring the law into line with good practice. 


Thanks to Doug Johnson for feedback on earlier drafts.  Any remaining mistakes or opinions are my own responsibility.


Related previous posts:

* Aggressive Bike Riders: Getting What We Ask For

* In Boston, Red Means Go!

* Bikes Are Vehicles; But They’re Not Cars








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