Motorcycle left-turn collisions

A car waiting to turn left, a motorcycle coming the other way, and a driver who decides there is time. It is the most common way riders are seriously hurt, and the driver almost always says the same sentence afterwards. This is general information, not legal advice.

The duty

A driver intending to turn left must yield to all vehicles approaching from the opposite direction that are close enough to constitute a hazard, and must continue to yield until the turn can be made with reasonable safety. Once the turn has lawfully begun after yielding and signalling, oncoming drivers must yield to the turning vehicle.

A motorcycle is a vehicle for this purpose, with the same right of way as a car. The rule does not soften because the approaching vehicle was small.

Sources: Veh. Code, § 21801 (left turn — duty to yield, and the oncoming driver's duty once the turn is lawfully under way); CACI No. 700 (a driver must keep a lookout for pedestrians, obstacles, and other vehicles), Judicial Council of California Civil Jury Instructions (2026 edition).

The car-on-car version, and the arrow-versus-ball distinction: left-turn accidents.

"I never saw the motorcycle"

This is said sincerely almost every time, and it is worth understanding rather than dismissing, because understanding it is how the case gets made.

A motorcycle presents a narrow frontal profile. It does not grow in the visual field the way a car does as it approaches, which makes distance and closing speed genuinely harder to judge. A driver scanning for a gap is looking for car-shaped objects, and a motorcycle can be looked at without being seen — the perception failure sometimes described as inattentional blindness.

None of which is a defence. The duty is to yield to traffic close enough to be a hazard, and a driver who did not perceive a vehicle that was plainly there failed to keep a proper lookout. Explaining the mechanism of a failure is not the same as excusing it. What it does change is the tone of the case: the driver is usually not a liar, and treating them as one distracts from the point that the duty was theirs.

The speed argument

Expect it. It is the only real defence available, and it works by shifting the question to whether the motorcycle was close enough to be a hazard when the turn began — which a very fast approach can genuinely affect.

Two systematic biases matter. Drivers who did not see a motorcycle coming routinely overestimate its speed afterwards, because the speed is what makes sense of their own failure. Riders routinely underestimate their own. Which is why neither account decides it, and physical evidence does:

• Damage severity and crush, which scale with closing speed.
• How far the motorcycle and the rider travelled after impact — often the single most useful measurement.
• Tyre marks, and the absence of them.
• Event data from the car, which many vehicles record.
• Signal timing and any camera footage.
• Helmet or bike-mounted camera footage, increasingly common.

Gear and evidence · how fault is decided.

What a rider can do afterwards

• Preserve the motorcycle unrepaired until it has been examined and photographed.
• Preserve helmet and gear, which carry impact evidence — see gear and evidence.
• Ask nearby businesses for footage in writing within days.
• Get witness names at the scene; left-turn crashes are usually seen by other waiting drivers.
• Do not estimate your speed to anyone, including the officer, unless you actually know it.

Common questions

Why is this the most common serious motorcycle crash?

Because a motorcycle presents a narrow profile that is easy to miss and hard to judge distance and speed against, and because a left turn asks a driver to make exactly that judgment. The impact then lands on the side of the car with the rider unprotected.

Does "I never saw him" help the driver?

Not as a defence. A driver turning left must yield to oncoming traffic close enough to be a hazard, and failing to see a vehicle that was there to be seen is a failure to keep a proper lookout rather than an excuse for one. It usually explains what happened without excusing it.

They say I was speeding. How is that resolved?

With physical evidence rather than estimates — damage severity, post-impact travel of both the bike and the rider, tyre marks, event data from the car, and camera footage. Drivers routinely overestimate the speed of a motorcycle they did not see coming, and riders underestimate their own.

Does the rider have any duty here?

The same as any road user — a reasonable speed for the conditions, attention, and a lookout. Where a rider was substantially over the speed limit that can carry a share of fault, because it affects whether the oncoming vehicle was close enough to be a hazard when the turn began.