Are you allowed to turn left here? (and perhaps other implied turn restrictions)

[Kacie Jane]

You're not supposed to turn left if there's two double-yellows.  This was taught in driver's ed.  It may be a Washington state thing, but it makes sense.

Just because it's taught in driver's ed doesn't mean it's the law.  (They often teach you how to be more careful than you're legally required to be.  Plus, some teachers, just like some drivers, are misinformed.)

http://blog.seattlepi.com/seattle911/2011/07/19/is-it-legal-to-turn-over-a-double-yellow-line/

The answer may surprise you.  RCW cite included.

[kphoger]

You're not supposed to turn left if there's two double-yellows.  This was taught in driver's ed.  It may be a Washington state thing, but it makes sense.

Just because it's taught in driver's ed doesn't mean it's the law.  (They often teach you how to be more careful than you're legally required to be.  Plus, some teachers, just like some drivers, are misinformed.)

http://blog.seattlepi.com/seattle911/2011/07/19/is-it-legal-to-turn-over-a-double-yellow-line/

The answer may surprise you.  RCW cite included.

Would there be any reason other than a U turn to turn across a double yellow, except to turn into an alley, private road, or driveway?

[colinstu]

Pretty sure this practice is illegal in California.

In Wisconsin however... it's almost encouraged at times.

[Kacie Jane]

Would there be any reason other than a U turn to turn across a double yellow, except to turn into an alley, private road, or driveway?

Possibly to park (side-of-the-street parking on the opposite side).  Other than that, I'm stumped.

Worth noting that KEK is correct that U-turns are prohibited across double yellows in Washington.  But left turns are not.

[NE2]

Eh? That article's about a single double yellow, not a double double yellow (probably with diagonal stripes between).

[Kacie Jane]

Eh? That article's about a single double yellow, not a double double yellow (probably with diagonal stripes between).

Okay, I'm an idiot and/or my brain failed to properly parse things like "double double".  Plus, I was thinking of an argument my father and stepmother got into regarding single double yellows.

Plus, I'm as baffled as KEK that it would ever be legal to cross diagonal stripes like that.  Why not just repaint this one as a TWLTL?

[vtk]

What if there's not enough room for a full TWLTL between the opposing through lanes, but you want to allow left turns to and from driveways? How would you stripe that, if not with a double double yellow (possibly with diagonal filler stripes)?

[Kacie Jane]

Okay, so I dug deeper, and I'm pretty sure that these are the laws in question:

Whenever any highway has been divided into two or more roadways by leaving an intervening space or by a physical barrier or clearly indicated dividing section or by a median island not less than eighteen inches wide formed either by solid yellow pavement markings or by a yellow crosshatching between two solid yellow lines so installed as to control vehicular traffic, every vehicle shall be driven only upon the right-hand roadway unless directed or permitted to use another roadway by official traffic-control devices or police officers. No vehicle shall be driven over, across or within any such dividing space, barrier or section, or median island, except through an opening in such physical barrier or dividing section or space or median island, or at a crossover or intersection established by public authority.

Whenever any highway has been divided into 2 or more roadways by leaving an intervening space or by a physical barrier or a clearly indicated dividing section so constructed as to impede vehicular traffic, every vehicle must be driven only upon the right-hand roadway unless directed or permitted to use another roadway by official traffic-control devices or police officers. No vehicle may be driven over, across, or within any such dividing space, barrier, or section, except through an opening in the physical barrier, or dividing section, or space, or at a cross-over or intersection as established by public authority.

Washington explicitly includes "median island not less than eighteen inches wide formed either by solid yellow pavement markings or by a yellow crosshatching between two solid yellow lines", while Illinois does not -- otherwise they're nearly word-for-word identical.

But I'm curious why said crosshatching would not be included under "clearly indicated dividing section" anyway.

[vdeane]

but you want to allow left turns to and from driveways?

How else are people supposed to get to those businesses?

[colinstu]

but you want to allow left turns to and from driveways?

How else are people supposed to get to those businesses?

Do an U-turn at the next intersection?

[kphoger]

but you want to allow left turns to and from driveways?

How else are people supposed to get to those businesses?

That's exactly vtk's point.  He was responding to the question of why it would ever be legal to turn left across a yellow cross-hatched flush median, and why it wouldn't be better to convert that flush median into a two-way left-turn lane.  The answer is that the median may not be wide enough for a turn lane, but may be too wide for a simple double yellow line.  His point was that drivers should still be allowed to turn into those businesses, but that yellow cross-hatching would be the best way to paint the median space.

[vdeane]

but you want to allow left turns to and from driveways?

How else are people supposed to get to those businesses?

Do an U-turn at the next intersection?

It's a good thing I've never seen that striping out here, because U turns are illegal in this part of the county.