Most collisions happen where paths cross. This is how to read an intersection on the way in, make a left turn across traffic without guessing, and get through a roundabout in the right lane.
About 7 minutes to read7 Ontario questions on this2 diagramsLast reviewed 2026-08-27
Worth remembering
Decide your lane and your plan before the intersection; the last few car lengths are for looking.
Scan left, right, then left again, because the closest oncoming traffic is on your left.
Amber means stop unless stopping is unsafe. Decide your answer while the light is still green.
Waiting to turn left, keep your wheels straight so a rear hit does not push you into oncoming traffic.
Judge a left turn gap by whether you can finish and clear their path, not by how far away the car looks.
Check your right mirror and blind spot for cyclists before every right turn.
Entering a roundabout, yield to traffic already circulating, pick the lane before you enter, and signal right on the way out.
Right turns on red and flashing green lights are two rules that differ by province. Check the guide for yours.
Read the intersection before you reach it
Every intersection tells you how it works before you arrive, if you look for the right things. Is it controlled by a signal, by signs, or by nothing at all? Which lane are you in, and what do the arrows painted on that lane allow? Is there a crosswalk, and is anyone standing at the curb waiting to use it? Are the vehicles ahead of you slowing for a reason you cannot see yet?
Get that reading done early, because the last few car lengths are for looking, not for deciding. Ease off the accelerator, cover the brake, and scan left, then right, then left again as you approach. The second look to the left matters because the traffic nearest to you on a two way road comes from your left, and a lot can change in the seconds it takes to check the other side.
Choose your lane well before the intersection rather than at it. Changing lanes inside an intersection is a fault on a road test in every province, and on a real road it puts you beside a driver who has no reason to expect you.
Signals, and the moment the light turns amber
A steady amber light means stop, unless you are already so close that stopping would be unsafe or would put you into the middle of the intersection. It does not mean hurry. The habit worth building is to decide as you approach any green light how you would respond if it changed, so the answer is ready before you need it. A green light that has been green since you first saw it is one that is due to change.
A green arrow protects the movement it points at, which means the traffic that would otherwise conflict with you is being held. A round green does not protect a left turn, so you must find your own gap. A red light means a full stop behind the line, and it stays a red light while you wait for that gap on an amber, so never edge over the line on red.
Two signal details differ across the country and are worth checking in the guide for your province. Right turns on a red light are allowed in most of Canada after a complete stop and a proper look, but not everywhere, and never where a sign forbids it. A flashing green light does not mean the same thing in every province: in some places it protects a turn, and in others it marks a crossing where people on foot control the signal. Being wrong about that one is dangerous, so look it up rather than assume.
The left turn across traffic
The unprotected left turn is the hardest ordinary thing a new driver does, and it is where a large share of serious intersection crashes happen. You signal early, move into the correct lane, and pull forward into the intersection when the way is clear enough to be there, keeping your front wheels pointed straight ahead. Straight wheels matter: if a vehicle hits you from behind while you wait, you are pushed forward rather than into oncoming traffic.
Then you judge the gap. The question is not whether the oncoming car is far away. It is whether you can finish the turn and be clear of their path before they reach you, at the speed they are actually travelling. Look past the first vehicle for a second one following close behind, and look through the intersection for someone coming the other way who also wants to turn left, because two left turning cars can hide each other completely.
Finish the turn by yielding to anyone crossing the road you are entering. Drivers concentrating on the gap in traffic often complete a good turn straight into a pedestrian who has had a walk signal the whole time. If the light turns red while you are waiting in the intersection, you still complete the turn when the oncoming traffic stops, because you are already committed and legally in the intersection.
Turning left across oncoming traffic
Your vehicle
Another vehicle
Where it goes
Wait inside the intersection with the front wheels straight until the gap is long enough to finish the turn.
A marked left turn bay and a painted island, seen from above. Most of what a knowledge test asks about is painted on the road rather than posted beside it.
Right turns, and the corner you cannot see
A right turn looks simple and hides two problems. The first is the cyclist or the scooter coming up on your right, in a bike lane or in the gap between you and the curb. Signal early, check your right mirror and your blind spot before you begin the turn, and do not cut across a marked bike lane where the paint tells you to yield instead.
The second is the pedestrian stepping off the corner you are turning into, often walking toward you and out of the line of sight your windshield pillar leaves you. Turn your head. Keep the turn tight enough to stay in your own lane and end in the nearest lane going your direction, unless markings say otherwise.
Roundabouts
Traffic in a Canadian roundabout moves counter clockwise, and everyone entering yields to traffic already going around. That single rule solves most of it. Slow down on approach, look to your left, and enter when there is a gap. Never stop inside the circle once you are moving, and never try to pass another vehicle in there.
Lane choice is the part learners get wrong. Choose your lane before you enter, based on the signs and arrows on the approach, not on where you happen to be. As a general pattern, the right lane serves the first exits and going straight through, and the left lane serves the later exits and turning back the way you came, but the markings on the ground govern and multi lane roundabouts vary. Signal right as you pass the exit before the one you want, and do not signal left on the way in unless the markings ask for it.
Large trucks need the whole width of the circle and sometimes ride up onto the paved apron around the island, so give them space rather than tucking in beside them. Cyclists may take the full lane in a roundabout, which is the safest thing for them to do. People on foot cross at the marked crossings on each approach, outside the circle, and they are yielded to on the way in and on the way out.
Choosing a lane at a roundabout
Your vehicle
Another vehicle
Where it goes
Traffic runs counter clockwise around the island, and you pick your lane on the approach rather than inside the circle.
What Ontario does differently
Everything above holds across Canada. This part does not, and it is the part a Ontario examiner can ask about.
Ontario rule
Right turn on red, and the left turn most people miss
Ontario allows a right turn on a red light. Come to a complete stop first, which means the wheels stop turning, then yield to pedestrians in the crosswalk, to cyclists coming up the curb lane and to cross traffic, and go only when the gap is genuinely there. Rolling through slowly is what drivers get ticketed for and it is also the answer the test marks wrong.
The permission disappears where a sign says so. Signs prohibiting a right turn on red are common downtown, near schools and at intersections with heavy foot traffic, and some of them apply only during posted hours. The sign is the authority. Read it before you creep forward.
The turn most drivers do not know about is the left one. From a one way street onto another one way street, Ontario allows a left turn on a red light after a complete stop, unless a sign prohibits it. It appears on the knowledge test and it is genuinely useful in older downtown grids.
One more Ontario signal to learn: a flashing green light, or a green arrow shown with the round green, gives you an advanced turn while opposing traffic is still held at a red. British Columbia uses a flashing green for something else entirely, so a driver arriving from the coast should treat the Ontario version as new information rather than a familiar friend.
Where people get this wrong
What people think
Amber means speed up and get through.
What is actually true
Amber is a warning that red is coming, and the legal instruction is to stop when you can do so safely. Accelerating into a changing light is how drivers meet the person who started early on the other side.
What people think
Turning my wheels left while I wait saves time.
What is actually true
It also aims you at oncoming traffic. If anyone hits you from behind while you wait, straight wheels send you forward into a gap and turned wheels send you into the vehicles you were waiting for.
What people think
A green light means I can turn left whenever there is a gap.
What is actually true
A round green lets you enter the intersection to wait, and you still yield to oncoming traffic and to people crossing the road you are turning into. Only a green arrow protects the turn.
What people think
In a roundabout you can change lanes to reach your exit.
What is actually true
Lane choice happens on the approach. Once you are in the circle, changing lanes cuts across a driver whose exit you are crossing, which is the collision roundabouts otherwise avoid.
What people think
I am stuck in the intersection on a red, so I have to reverse or sit there.
What is actually true
If you entered legally to make a left turn and the light changed, complete the turn once oncoming traffic has stopped. Never reverse in an intersection.
Check yourself
Three questions from the Ontario bank on intersections and turns. Answer them in your head first, then open the answer to see the rule it comes from.
Intersections and turns1 of 3
The light ahead turns amber as you approach. You are close enough that stopping would mean braking hard, and a car is following you closely.
ACarry on through the intersection with care, since you cannot stop safely
BBrake hard anyway, because an amber light means stop
CSpeed up so you are clear before the light turns red
DStop with your front over the crosswalk to keep clear of the intersection
Show the answer
The answer is A. Carry on through the intersection with care, since you cannot stop safely
Amber means stop if you can do it safely. When you are so close that stopping would be violent or would put the driver behind into your rear bumper, going through is the safer choice. The real lesson comes earlier: read the light from further back and cover the brake, so you are rarely caught in that zone at all.
Highway Traffic Act (Ontario)
Intersections and turns2 of 3
You are first in line at a signal, waiting to turn left, when the green light starts flashing.
AThe signal has failed, so treat the intersection as a four way stop
BYield to all other traffic before entering, as you would at a flashing amber
COncoming traffic is being held at a red, so you may turn left, go straight or turn right
DLeft turns are barred and you may only go straight or turn right
Show the answer
The answer is C. Oncoming traffic is being held at a red, so you may turn left, go straight or turn right
A flashing green in Ontario is an advanced green: the drivers facing you are being held at a red, so your left turn is protected for that time. Do not confuse it with British Columbia, where a flashing green marks a crossing controlled by pedestrians. Look before you turn anyway, because a protected turn only protects you from drivers who obey their own light.
Highway Traffic Act (Ontario)
Intersections and turns3 of 3
You want to turn right at a red light. No sign at the intersection says anything about turning on red, and a pedestrian is waiting at the corner on your right.
ATurn without stopping if the way is clear, since a red allows a right turn
BStop completely, let the pedestrian cross, then turn once the way is clear
CWait for the green, because a pedestrian is waiting
DRoll slowly around the corner while watching the pedestrian
Show the answer
The answer is B. Stop completely, let the pedestrian cross, then turn once the way is clear
A right turn on red is allowed only after a full stop, and only where no sign prohibits it. The stop is what buys you the time to look for people crossing and for traffic coming from your left. Waiting for the green is not wrong, but rolling the corner is, and it is the most common way this turn goes badly.
Highway Traffic Act (Ontario)
Now go and answer some questions
The Ontario bank holds 7 questions on intersections and turns. Answering them now, while the lesson is fresh, is how you find the parts that only felt clear.
