The Shared Left-Turn Lane in the Rain
It is 11 p.m. and raining hard on a four-lane arterial. You are northbound, planning a left turn into a shopping-center driveway. The road has a shared center left-turn lane, marked by solid white lines on both sides with left-turn arrows painted inside it. A car is tailgating you about one car length back. A southbound car is approaching roughly 150 feet away. Water is pooling, and the arrows and white lines glare and then fade under your headlights just before the driveway; past the fade you can barely see where the lane edges are. There is no signal at the driveway, and you already passed the previous entrance.
1. May you cross the solid white lines into the shared center lane, and what may that lane legally be used for?
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Yes - but only for a turn, and only when you are close to it.
- The solid white lines mark the edges of a two-way left-turn bay, not a travel lane. Solid lines mean do not cross except for the movement the lane exists to serve.
- Permitted uses: decelerating to turn left into the driveway or a side street, and entering the roadway from a driveway or side street to turn left.
- Prohibited uses: using it as an acceleration/travel lane, passing, or drifting into it hundreds of feet before your turn.
- Practical rule: signal, enter the bay shortly before the driveway, and keep your wheels straight while you wait so a rear-end hit will not push you into oncoming traffic.
2. The southbound car is about 150 feet away. How do you decide whether to commit to the turn?
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Do not commit on a guess - use the bay to wait.
- At about 40 mph the oncoming car covers roughly 59 feet per second. If you need about 4 seconds to turn and clear the lane, it will travel around 235 feet in that time - more than the 150 feet you have.
- Wet pavement lengthens your own acceleration and stopping distances, so the real gap you need is larger than on dry asphalt.
- The correct move is to enter the bay, stop, and wait for a gap you can clear without the oncoming driver lifting off the throttle. Never assume the other driver will slow for you.
- If a car behind you is impatient, that changes nothing: the tailgater's hurry is not a legal or physical reason to turn into a short gap.
3. The markings fade and glare in the standing water. How do you keep your lane position, and what do you do if you lose the boundary?
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Slow down until the visible distance matches your speed, and steer by stable references.
- Fix on the right edge line or curb rather than on oncoming headlights; glare destroys your night vision and hides the lane edge.
- Reduce speed before the fade so you could stop within the distance you can actually see. If you cannot see the boundary at all, a crawl is the only defensible speed.
- Brake early and smoothly rather than late and hard, because the tailgater has left you almost no margin.
- If you overshoot or drift, straighten out and continue to the next safe entrance instead of making a panic turn across a double line or into oncoming traffic.