Left turns and intersections for new drivers: gaps, signals and habits
How to read left turn signals, judge gaps in seconds and spot people in crosswalks
Picture a new driver waiting to turn left on a green ball while a pickup in the opposite turn lane hides the lane beside it. Someone is walking toward the far crosswalk. The driver behind just tapped the horn. The teen has only seconds to sort it all out.
Children’s Hospital of Philadelphia (CHOP) lists left turns among the most common crash types for newly licensed teens [3]. This guide explains why, then gives you a turn checklist, an error table and a practice plan for parents who supervise.
Why intersections and left turns are so risky
A left turn asks you to cross oncoming lanes and then a crosswalk, often while the signal is changing. In 2022, 12,036 of the 42,514 U.S. traffic deaths involved an intersection or driveway, according to FHWA’s review of federal crash records [1]. That is about 28%. More than 2,000 of those killed were pedestrians (our calculations from FHWA’s tables) [1].
In on scene investigations from 2005 to 2007, the National Highway Traffic Safety Administration (NHTSA) found turning left was the critical event in about 22% of crashes [2]. Crossing straight through was about 13%. The leading driver errors at intersections were about seeing, not steering [2]:
- Inadequate surveillance, meaning the driver did not look or did not look well enough: 44.1%
- A false assumption about what another driver would do: 8.4%
- Turning with an obstructed view: 7.8%
- Misjudging a gap or another vehicle’s speed: 5.5%
Teens show the same pattern in a AAA Foundation for Traffic Safety study of in car crash video from 2007 to 2013. Angle crashes made up 290 of 727 teen crashes with another vehicle. Inadequate surveillance appeared in 60% of them [4].
Notably, not one of those angle crashes was coded as a misjudged gap. But missed looks and failures to yield were common [4]. Since young drivers also struggle to judge speed and distance [12], training has two jobs: build a complete scan, then judge what it finds.
Know your signal: green ball, green arrow or flashing yellow arrow
The federal Manual on Uniform Traffic Control Devices (MUTCD) sets the national meaning of each signal [5]:
Comparison compiled by Safety Behind the Wheel Foundation
| Signal you face | What it allows | What you still must do |
|---|---|---|
| Green arrow | A protected turn; oncoming traffic should be stopped | Yield to anyone still in the crosswalk or intersection [5] |
| Flashing yellow arrow | A turn that is allowed but not protected | Yield to oncoming traffic and pedestrians, then turn in a safe gap [5, 8] |
| Green ball | Straight, right or left, with no protection for turns | Yield to oncoming traffic and pedestrians [5, 7] |
| Steady yellow arrow or ball | The current movement is ending | Stop if you safely can; if already waiting in the intersection, finish once oncoming cars stop [5, 7, 8] |
| Red arrow | No turn in that direction | Wait; California, for example, bans turning on a red arrow [8] |
The green ball fools many drivers. In federal research published in 2003, more than 2,400 drivers took photo based tests. The green ball had the lowest understanding of the left turn displays tested [6]. Only about half understood it. The report went on to recommend the flashing yellow arrow, now part of the MUTCD [5, 6].
Have your teen say one phrase out loud at every signal: “Arrow means protected. Ball or flashing yellow means yield.”
Watch for the yellow trap. At some signals, your green ball turns yellow while oncoming drivers keep a green, often because their side is getting a turn arrow [6]. A waiting driver may assume oncoming cars must stop and turn into their path. So finish only after oncoming traffic has actually cleared or stopped [7].
Right turn on red and left turn on red
Under the MUTCD, unless a sign says otherwise, you may turn right on red after a full stop, or left from one one way street onto another [5]. California’s handbook adds that a right turn on red requires yielding to pedestrians [8].
A classic right on red mistake is watching left for a gap while someone steps off the right hand curb. So make your last look to the right.
Set up the turn: lane, waiting spot and straight wheels
Choose your lane early, signal, and do most of your slowing before the stop line. Where you wait depends on your state: New York lets you pull into the intersection on a green if no one ahead is turning left. You then finish when oncoming traffic clears or stops for a red [7].
Wherever you wait, keep your wheels straight, because if they point left and someone rear ends you, you could be pushed into oncoming traffic [7].
Then check your exit, since California’s handbook says not to enter an intersection unless you can get completely across before the light turns red [8].
Judge gaps in seconds, not distance
Engineers think about gaps in time. California’s highway design manual assumes a passenger car turning left from a stop needs a 7.5 second gap. It adds 0.5 seconds for each extra lane and more for trucks. But these are design assumptions, not a promise of safety [9].
Drivers, however, tend to judge distance. In a 2007 simulator study of left turns from a stop sign, drivers accepted shorter gaps more often when traffic was faster. The authors concluded that drivers focused more on a car’s distance than on its speed. The table below shows why that matters [10]:
Comparison compiled by Safety Behind the Wheel Foundation
| Oncoming speed | Feet covered per second | Time until a car 400 feet away arrives | Distance needed for an 8 second gap |
|---|---|---|---|
| 25 mph | about 37 | about 11 seconds | about 290 feet |
| 35 mph | about 51 | about 8 seconds | about 410 feet |
| 45 mph | about 66 | about 6 seconds | about 530 feet |
| 55 mph | about 81 | about 5 seconds | about 650 feet |
Motorcycles make this harder: in 2024, there were 3,396 fatal crashes between a motorcycle and one other vehicle. In 45% of them, the other vehicle was turning left while the motorcycle went straight, passed or overtook [11].
Our teaching margin: learners should start with at least 8 seconds for one oncoming lane and add at least 1 second per extra lane. Add more at night or in rain. Remember that this coaching rule sits above the design value rather than being a legal standard.
The gate count drill
- From the passenger seat, pick a “gate,” such as a pole on the oncoming side.
- Count “one thousand one, one thousand two” from when a car passes the gate until it reaches your turn path. Repeat with 5 cars.
- Move your gate until normal traffic takes about 8 seconds.
- If the next car has not reached the gate, you have about 8 seconds at normal speed. But fast cars and motorcycles need a farther gate.
- Have the teen call “go” or “wait” while the parent counts. Switch seats once the calls match.
When you cannot see, you cannot go
NHTSA’s code “turned with obstructed view” describes a driver who could not see approaching traffic, usually because another vehicle was in the way [2]. At stop signs, drivers 24 and younger made this error significantly more often than expected [2].
At signals, the classic blocker is the opposing left turner, which can hide through traffic in the next lane. Engineers sometimes shift turn lanes so that waiting cars stop out of each other’s sight lines [12].
Buses, parked vehicles, hedges, hill crests, glare and your own windshield pillar can also hide traffic. Use these moves when your view is blocked:
- Treat the hidden lane as full, because a lane you cannot see is unknown, not empty.
- Wait for the blocker to turn, or finish once oncoming traffic stops for its red [7].
- Ignore a friendly wave, since that driver cannot see the lane beside them either.
- Rock forward and back in your seat to see around the pillar, especially for people in the crosswalk.
- Choose a route with a green arrow, or make three right turns instead.
Crosswalks: finish your scan where the turn ends
Every left turn ends in a crosswalk. FHWA notes that drivers hunting for a gap on a green may miss a pedestrian there [12].
Vehicle design adds risk, too. The Insurance Institute for Highway Safety (IIHS) studied nearly 4,500 police reported pedestrian crashes during left turns in seven states. Vehicles with large driver side blind zones had a 70% higher risk of striking a pedestrian while turning left [14].
A leading pedestrian interval gives walkers a 3 to 7 second head start. So people may already be crossing when your light turns green [15]. On any green, including an arrow, you must yield to people lawfully in the crosswalk [5].
Build a last look into every turn: just before your wheels turn, check the crosswalk you are entering, including both curbs and any cyclists.
Signal timing: stale greens, yellow lights and red light runners
Driving instructors call a light that was already green when you first saw it a stale green. It could turn yellow at any moment. A pedestrian countdown can hint at how much time is left.
FHWA’s 2004 signal guide notes that yellow lights normally last 3 to 6 seconds, timed with an engineering formula [12, 13]. At 35 mph, you cover about 51 feet each second. So a 4 second yellow passes in about 205 feet (our calculation).
FHWA describes a dilemma zone, the stretch before the stop line where a sudden yellow forces a hard choice between stopping and going [12]. Speeding makes it worse, because at 45 mph in a 35 mph zone you need about 65% more braking distance (our calculation).
Use this routine every time you approach a stale green:
- Ease off the gas and cover the brake.
- Pick your point of no return, the last spot where you could stop smoothly.
- If the light turns yellow before that point, stop, as California’s handbook advises when you can do so safely [8].
- If you are past it, keep a steady speed and never speed up to beat the red.
Red light runners. In 2024, 1,119 people died in crashes involving red light running and more than 141,000 were injured, IIHS reports [13]. Half of those killed were pedestrians, cyclists or people in other vehicles. In a 2024 AAA Foundation survey, 80% of drivers called it very or extremely dangerous to run a fresh red they could have stopped for. Yet 27% admitted doing it in the past 30 days [13].
That is why a fresh green needs a pause and look. California’s handbook tells drivers to look left, right and ahead before entering an intersection [8]. If you are first in line, take one second to look left, right and left again.
The Five S left turn check
Run this check at every unprotected left turn, with your wheels straight and your foot on the brake.
If any answer is no, wait, because a horn behind you does not make the gap any bigger.
Common novice intersection errors, why they happen and the fix
Comparison compiled by Safety Behind the Wheel Foundation
| Error | Why it happens | The fix |
|---|---|---|
| Turning on a green ball as if it were protected | The ball and arrow look alike, and many drivers misread the ball [6] | Say “ball means yield” out loud at each signal |
| Judging a gap by distance | People sense distance better than speed [10] | Count seconds from a fixed gate |
| Turning past an opposing left turner | A lane you cannot see looks empty | Treat hidden lanes as full and wait |
| Missing the pedestrian at the end of the turn | Eyes stay locked on oncoming cars [12] | Take a last look at the crosswalk before turning |
| Turning the wheels while waiting | It feels like getting ready | Keep wheels straight until you go [7] |
| Going the instant the light turns green | Green feels like a guarantee | Pause and look left, right and left again |
| Speeding up on a stale yellow | Fear of getting stuck at the red | Plan the point of no return and ease off early |
| Assuming oncoming traffic also has yellow | The yellow trap [6] | Finish only when oncoming cars have stopped |
| Missing a motorcycle | Small vehicles are hard to see and judge [11] | Look twice and add margin |
| Rolling into a right turn on red | Attention is on the gap to the left | Stop fully and make your last look to the right |
| Giving in to a honk | Social pressure | Run the Five S check again and wait |
A practice plan for parents
Build skill in stages. Move ahead only when your teen handles about 10 turns in a row at a stage without prompts from you.
- Passenger seat coaching: You drive while your teen names each signal and counts gaps aloud, such as “Ball, yield, 9 seconds, go.”
- Quiet stop sign intersections: Practice right turns, then left turns, in light daytime traffic.
- Protected left turns: Use green arrows at signals during quiet hours.
- Simple unprotected turns: Turn on a green ball or flashing yellow arrow, with one oncoming lane at 25 to 35 mph.
- Busier intersections: Add more oncoming lanes, opposing turners, busy crosswalks and speeds of 40 to 45 mph.
- Hard conditions: Add night, rain, rush hour and left turns from a stop onto fast roads.
Agree on one calm cue, such as “wait,” that means do not start the turn. After you park, ask what the signal was, what your teen could not see and why they took or skipped each gap. Roundabouts replace the left turn across traffic with a loop, so treat them as their own lesson. If your teen keeps missing pedestrians or freezing at gaps, book a professional lesson.
Frequently asked questions
Do you have to yield when turning left on a green light?
Yes. On a green ball, you must yield to oncoming traffic close enough to be a hazard and to people in the crosswalk [5, 7]. Only a green arrow protects your turn.
What does a flashing yellow arrow mean?
It allows a left turn that is not protected. So you must yield to oncoming traffic and pedestrians, just as on a green ball [5, 8].
How many seconds do you need to turn left across traffic?
Road designers assume a passenger car turning left from a stop needs about 7.5 seconds, plus 0.5 seconds per extra lane [9]. New drivers should practice with at least 8 seconds for one lane.
Should you wait in the middle of the intersection to turn left?
It depends on your state: New York allows it on a green if no one ahead of you is turning left [7]. Finish only when oncoming traffic clears or actually stops.
Can you turn right on a red arrow?
It depends on the state: California’s handbook says not to turn on a red arrow [8]. So check your state manual and obey posted signs.
The bottom line
Recommendation from Safety Behind the Wheel Foundation
Most intersection crashes begin with a missed look, so teach a full scan before speed. Know your signal, count gaps in seconds, treat hidden lanes as full, take a last look at the crosswalk and pause on every fresh green.
Related articles
- Hazard perception for new drivers: how to scan and spot trouble early
- Supervised driving practice plan: a 6 stage guide for parents and teens
- Right of way rules: four way stops, crosswalks and roundabouts explained
- Pedestrian safety for drivers: how to spot, yield to and protect walkers
- Motorcycle awareness for drivers: how to spot riders and avoid crashes
Sources and further reading
- 1Federal Highway Administration (FHWA). Intersection Safety: About. Updated July 28, 2026. highways.dot.gov/safety/intersection-safety/about
- 2National Highway Traffic Safety Administration (NHTSA); Choi EH. Crash Factors in Intersection-Related Crashes: An On-Scene Perspective. DOT HS 811 366. September 2010. crashstats.nhtsa.dot.gov/…/811366
- 3Children’s Hospital of Philadelphia (CHOP), Teen Driver Source. Basic Facts About Teen Crashes. Accessed October 2026. teendriversource.research.chop.edu/…/basic-facts-about-teen-crashes
- 4AAA Foundation for Traffic Safety (Carney C, McGehee DV, Harland K, Weiss M, Raby M). Using Naturalistic Driving Data to Assess the Prevalence of Environmental Factors and Driver Behaviors in Teen Driver Crashes. March 2015. aaafoundation.org/…/2015TeenCrashCausationReport.pdf
- 5Federal Highway Administration (FHWA). Manual on Uniform Traffic Control Devices, 11th Edition, Part 4: Highway Traffic Signals (Sections 4A.03 and 4A.04). December 2023. mutcd.fhwa.dot.gov/pdfs/11th_Edition/part4.pdf
- 6Transportation Research Board, National Cooperative Highway Research Program (Brehmer CL, Kacir KC, Noyce DA, Manser MP). Evaluation of Traffic Signal Displays for Protected/Permissive Left-Turn Control. NCHRP Report 493. 2003. onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_493.pdf
- 7New York State Department of Motor Vehicles. Driver’s Manual, Chapter 5: Intersections and Turns. Accessed October 2026. dmv.ny.gov/…/chapter-5-intersections-and-turns
- 8California Department of Motor Vehicles. California Driver’s Handbook: Laws and Rules of the Road. Updated June 2025. dmv.ca.gov/portal/handbook/…/laws-and-rules-of-the-road
- 9California Department of Transportation (Caltrans). Highway Design Manual, Chapter 400: Intersections at Grade (Topic 405.1, Table 405.1A). Updated September 29, 2023. dot.ca.gov/…/chp0400-092923-a11y.pdf
- 10Yan X, Radwan E, Guo D. Effects of Major-Road Vehicle Speed and Driver Age and Gender on Left-Turn Gap Acceptance. Accident Analysis & Prevention 39(4):843 to 852. 2007. sciencedirect.com/science/article/pii/S0001457506002223
- 11National Highway Traffic Safety Administration (NHTSA). Traffic Safety Facts: Motorcycles, 2024 Data. DOT HS 813 824. July 2026. crashstats.nhtsa.dot.gov/…/813824
- 12Federal Highway Administration (FHWA). Signalized Intersections: Informational Guide (Chapters 2, 4, 9 and 12). FHWA-HRT-04-091. August 2004. fhwa.dot.gov/publications/research/safety/04091
- 13Insurance Institute for Highway Safety (IIHS). Red Light Running. Updated July 2026. iihs.org/research-areas/red-light-running
- 14Insurance Institute for Highway Safety (IIHS). Vehicles With Big Blind Zones Spell Danger to Pedestrians During Left Turns. News release, November 19, 2025. iihs.org/news/detail/vehicles-with-big-blind-zones…
- 15Federal Highway Administration (FHWA). Proven Safety Countermeasures: Leading Pedestrian Interval. FHWA-SA-21-032. Accessed October 2026. highways.dot.gov/…/leading-pedestrian-interval
This article reflects the safety priorities of driver education and traffic engineering. It is general education, not legal or professional advice for any individual driver. Laws, signal designs and crash data change, so verify details with official sources such as your state DMV. Reviewed October 2026.
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