A Yellow Traffic Light Means Stop

Yellow Traffic LightBelieve it or not, in British Columbia a yellow traffic light tells you that you must stop before you enter the intersection! Yes, I know that there is one caveat to that statement, and it is "unless the stop cannot be made in safety." The onus is on the driver that does not stop for the yellow light to show that it was unsafe if they are involved in court proceedings because of their decision.

Anticipating a Yellow Light

Is anyone able to tell me what a stale green light is? That's right, it's a traffic signal that will soon be turning from green to yellow. An example of a stale green light would be one that you have not seen turn green so that you don't know how long it has been that way, one that has a solid red hand "don't walk" signal facing the same direction of travel or perhaps the cross street has many vehicles waiting for the red.

Shadowing Your Brake

The proper response when approaching a stale green light is to shadow the brake pedal. This means lifting your foot off of the accelerator and hovering it over the the brake. If a stop is needed, you are already almost there as you are beginning to slow and ready to brake.

Know What's Behind You

A defensive driver knows about the traffic behind them when they drive. They actively adjust their position and speed to take into account poor driving behaviours shown by those around them. These actions minimize the hazard of being rear ended when stopping for a traffic signal.

Planning to Stop

A bad habit exhibited by many drivers that increases risk is the race to the traffic light. Speed is maintained until the last moment and then the brakes are applied. If the driver behind is not paying attention a collision may result. Beginning to slow in anticipation of the change is a safer choice to make.

Advance Warning Lights

Advance warning lights preceding some intersections are timed to allow a driver facing them to come to a safe stop for the pending signal change. 

stop ahead warning lights and sign


A traffic ticket for failing to stop for a yellow light will cost $167 and 2 penalty points.

I usually agree with most of what you say, but I have a problem with this "shadowing" technique.

Back when I was a driving instructor, I built a "reaction time meter". Basically a stop light with red, amber, green, hooked up to a digital 1,000ths of a second timer, and push buttons for Start / Stop. I would set the light to green, and have the student press a dummy button. Under the table, I would change the light from green to amber or red, starting the timer, and the student would move his hand to and push another button to stop it. I graphed every student, and over time developed an almost perfect bell curve, from just under 1/2 sec to just over 1 sec.

The purpose was to teach students :

  1. not to tailgate, because the person in front may have faster reaction time, and they would rear end them in a quick stop
  2. to watch the driver behind, and if they were tailgating, to leave lots of space up front to allow themselves time for a slower stop

A vehicle moves about 1 foot per second per kph. So at 50 (or more likely 63) kph, a driver will take about 50 (or 63) feet to react to the light change, before mashing the pedal. If the driver "shadows" the pedal, he will stop 50 or so feet sooner than the car behind. Probably leading to a rear ender.Especially since many aggressive drivers automatically hit the gas first, expecting the driver ahead to "run the yellow".

I taught my students, that if they felt the green was really getting "stale", to cover the brake pedal, but also push just enough to activate the brake lights, thus warning the driver behind that they were preparing to stop if necessary.    If the light stayed green, they would simply coast through.

The whole concept of being able to predict a light change through the "stale green" concept is a real epiphany for most new drivers. And probably a lot of ‘experienced’ ones as well, it seems. Good of you to bring it up in your column.

The introduction of "dedicated" traffic lights also introduces an opportunity to predict an imminent color change.

If I am on a "dedicated" route, and see a car approach from a cross street, I know the light will change in ( from about) 8 to 15 seconds. If I am farther away than that, I can virtually be assured that it will change.

What are your thoughts on the proposal for more traffic circles or "roundabouts" ? Good or bad idea?

... that a Yellow Arrow essentially means the same thing as a Solid Yellow Light.

Sure as hell doesn't mean boot it into your late left turn, just when the pedestrians are likely to enter your path on their fresh 'Walk' signal.

I'm just sayin' ...

If  a vehicle has regenerative braking that "kicks in as soon as the driver takes their foot off the accelerator pedal." due to the settings, the driver might not have to touch the brake pedal to stop. More at https://www.tomsguide.com/reference/what-is-regenerative-braking-and-how-does-it-work

The brake lights come on too if it's a "Tesla Model 3 regenerative braking system. When you remove your foot from the pedal, the brake lights do come on. The mechanical brake pedal is not required to make that red glow."; but not all do? https://www.greencarfuture.com/electric/does-regen-braking-turn-on-brake-lights

I also check the crosswalk signal. Some of the newer ones even have a count down for the pedestrians. If it has a flashing red hand you know that the light is going to chance very soon.

Years ago I attended a safety lecture put on by MacLure's cabs. I was working for them at the time. It was part of a mult-part defensive driving course.

One of the things I remember was the idea that as you approach an intersection, you mark a point that is a "go/no-go" point. If the light turns yellow before you reach that point, you can make a smooth stop without unduly discomforting your passengers. If you pass that point, you know that you can continue without acceleration.

This assumes that other traffic allows for this. The only times I've every had to modify this is when people are in the intersection already and waiting to turn left across my path.

I still use this today.

If I am approaching a stale green light, I flash my brake lights to let the driver behind me know I may be stopping, has worked for years.

I can’t believe the number of drivers these days who will still run a light when the advanced amber warning lights are flashing.