A vehicle is positioned in a controlled intersection waiting to turn left from a two-way road. The light turns amber, and the driver waits for traffic to legally pass through the intersection. Assuming the rest of the traffic will stop, the vehicle proceeds with the left turn. However, another vehicle proceeds through the "late" amber light and crashes into the vehicle turning left.

In Ontario, the Highway Traffic Act states the following:

Every driver approaching a traffic control signal showing a circular amber indication and facing the indication shall stop his or her vehicle if he or she can do so safely, otherwise he or she may proceed with caution. R.S.O. 1990, c. H.8, s. 144 (15)

The driver or operator of a vehicle upon a highway before turning to the left or right at any intersection or into a private road or driveway or from one lane for traffic to another lane for traffic or to leave the roadway shall first see that the movement can be made in safety ... R.S.O. 1990, c. H.8, s. 142 (1)

In a BC ruling, Domil v. Cheung, the supreme court noted the following:

[98] In Kokkinis, Madam Justice Newbury said the following about an accident occurring at another busy intersection in Vancouver (at para. 10):

…An amber light is not, as the current witticism suggests, a signal to accelerate or to pass traffic that is slowing to a stop. Indeed, as Mr. Justice Esson noted in Uyuyama, in a busy city like Vancouver and at a busy intersection like 25th and Granville, an amber is likely the only time one can complete a left turn. Drivers approaching intersections must expect that this will be occurring. Putting a burden on a left-turning driver to wait until he or she sees that all approaching drivers have stopped would, in my view, bring traffic to a standstill. We should not endorse such a result.

[99] Madam Justice Newbury’s observations apply with equal force to the busy intersection of Main Street and King Edward.

In this case, the driver "running" the amber light was found to be 100% at fault. I cannot find any similar rulings in Ontario, however.

Would a similar ruling be made in Ontario, i.e. are drivers allowed to assume vehicles will stop at an amber light when it is safe to do so, and what rulings have been made on similar scenarios in the past?

  • 2
    Maybe legally, but as far as safety, the answer to "Is it correct to assume drivers will...?" is always "no."
    – Someone
    Jul 12, 2022 at 1:48
  • 2
    The idea that an amber light would give a turning vehicle the right of way is daft. The quoted case seems to turn on the idea that the driver going straight probably ran a red light.
    – Tiger Guy
    Jul 12, 2022 at 3:35
  • 2
    @TigerGuy Well, the Kokkinis v Hall case mentioned in the case establishes that "The duty on a left turning driver pursuant to section 174 of the MVA is not absolute. It is well established that left turning drivers are entitled to rely on the assumption that other drivers will obey the rules of the road, absent any reasonable indication to the contrary. In particular, a left turning driver is not required to wait until he or she sees that all approaching drivers have stopped: …". See para. 49 of this Lee v. Tse Jul 12, 2022 at 4:10
  • A few days before I got my driving license, the instructor asked me to turn into a one way road. I asked him "can I assume there will be no oncoming traffic?" He just pointed to the bicycle coming towards us :-)
    – gnasher729
    Jul 13, 2022 at 12:19
  • 2
    I once assumed (quite reasonably) that if I stop safely at a red traffic light, then a car several seconds behind me would also stop. And that assumption was false.
    – gnasher729
    Jul 13, 2022 at 12:32

2 Answers 2


I'm not convinced that there is a uniform rule. Usually, liability for a traffic accident is considered in light of the facts as a whole to determine if a driver is negligent.

The black letter law cited in the question, which is likely to be identical in all Canadian jurisdictions, is that the driver "may proceed with caution". But, what constitutes appropriate caution could vary based upon visibility, road conditions, traffic speed, the skill of the person driving the car, and any number of other possible conditions.

If you know the driver of the other car that would influence a great deal whether you were being cautious or not in making a decision, as would the knowledge of someone who is regularly at that intersection about how others typically behave there.


In road traffic, many times you can assume things quite reasonably, but your assumptions will be wrong. There is always the rule that if you can avoid damage, you must avoid damage. So you can assume that someone doesn't run a yellow traffic light, but if they do and take your right of way, you must stop to avoid an accident. In Germany, if you go legally over 80mph on a motorway, the law says you must assume that others make mistakes, and drive in a way so that everyone is safe, even if they make mistakes and break the traffic laws.

My private opinion is that many traffic accidents happen not because one person makes a mistake, but because one makes a mistake, and someone else cannot compensate for it.

  • +1 A green light almost never means one has the right of way. All it means is that other motorists have a legal obligation to yield the right of way if the Laws of Newton would allow them to do so. In most jurisdictions, a green light merely grants permission to proceed once a motorist actually has the right of way, i.e. no other vehicle has a trajectory that would collide with that of the vehicle that received the green light.
    – supercat
    Apr 17, 2023 at 17:38

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