For police, not wearing seat belts can be fatal mistake

[kphoger]

By "with no restrictions", I mean available to you and me and everybody to use; my car doesn't have roof lights, sorry to say.  Besides which, roof lights plus more accel/decel room is definitely safer than roof lights with no accel/decel room.

You were discussing emergency crossovers on Interstate highways.  Non-official use is prohibited.  On a 70-mph design, accell/decell lanes would be about 1,000 feet long, and that would be wasteful in that case.

Crossovers open the the public on non-freeways are a different subject, and they should have ample accell/decell lanes.

No, I was referring to crossovers on freeways in general.  The two Google maps examples I posted upthread are not both on Interstates.  In fact, one of them isn't even in the United States (though, to be fair, that one isn't a full freeway, but this one farther south is on a freeway stretch of the same route; here is an example from another another freeway route in a neighboring state).

Apparently other countries don't find accel/decel lanes space to be a waste, but rather a necessary component of accommodating traffic movements.  Furthermore, the length of said accel/decel lanes could probably be shortened due to light use, i.e. the fact that few drivers would actually need to use them.

[Beltway]

Crossovers open the the public on non-freeways are a different subject, and they should have ample accell/decell lanes.

No, I was referring to crossovers on freeways in general.  The two Google maps examples I posted upthread are not both on Interstates.  In fact, one of them isn't even in the United States (though, to be fair, that one isn't a full freeway, but this one farther south is on a freeway stretch of the same route; here is an example from another another freeway route in a neighboring state).

Apparently other countries don't find accel/decel lanes space to be a waste, but rather a necessary component of accommodating traffic movements.  Furthermore, the length of said accel/decel lanes could probably be shortened due to light use, i.e. the fact that few drivers would actually need to use them.

A freeway would be equivilent to an Interstate highway in that a crossover is for official use only.

How does posting a few examples demonstrate what is customary design for crossovers on freeways inside or outside of the USA?

[kphoger]

A freeway would be equivilent to an Interstate highway in that a crossover is for official use only.

Huh?  Crossovers aren't necessarily for official use only on non-Interstate freeways.  That may be the law in all or most of the states here in the US (I'm not about to look them all up), but it certainly isn't the way things are everywhere in the world.

How does posting a few examples demonstrate what is customary design for crossovers on freeways inside or outside of the USA?

It doesn't.  I never intended it to.  My statement, 'Apparently other countries don't find accel/decel lanes space to be a waste...' was intended to be backed up by common knowledge, not proven by my earlier Google Maps links.  I thought it was common knowledge that jurisdicions where construction money is harder to come by (developing nations) frequently prefer a combination of RIROs and crossovers to grade-separated interchanges on their freeways–furthermore that the crossovers frequently have accel/decel space provided.  I forget that not everyone spends insane amounts of time 'driving' highways in foreign countries on Google satellite imagery the way I've been known to do.

[Beltway]

A freeway would be equivilent to an Interstate highway in that a crossover is for official use only.

Huh?  Crossovers aren't necessarily for official use only on non-Interstate freeways.  That may be the law in all or most of the states here in the US (I'm not about to look them all up), but it certainly isn't the way things are everywhere in the world.

The definition of 'freeway' in the USA would not include a highway with a crossover open to the public, as that would be an at-grade intersection.

How does posting a few examples demonstrate what is customary design for crossovers on freeways inside or outside of the USA?

It doesn't.  I never intended it to.  My statement, 'Apparently other countries don't find accel/decel lanes space to be a waste...' was intended to be backed up by common knowledge, not proven by my earlier Google Maps links.  I thought it was common knowledge that jurisdicions where construction money is harder to come by (developing nations) frequently prefer a combination of RIROs and crossovers to grade-separated interchanges on their freeways–furthermore that the crossovers frequently have accel/decel space provided.  I forget that not everyone spends insane amounts of time 'driving' highways in foreign countries on Google satellite imagery the way I've been known to do.

I don't see how it is possible to generalize about highway designs all over the world.  There is great variation in how things are done.

What you cited as "common knowledge"... I have been reading roads forums for 15 years, and that is the first such comments that I have seen.

[NE2]

The definition of 'freeway' in the USA would not include a highway with a crossover open to the public, as that would be an at-grade intersection.

It's an edge case, like a RIRO intersection.
https://www.aaroads.com/forum/index.php?topic=4875.0

[Beltway]

The definition of 'freeway' in the USA would not include a highway with a crossover open to the public, as that would be an at-grade intersection.

It's an edge case, like a RIRO intersection.
https://www.aaroads.com/forum/index.php?topic=4875.0

I wouldn't put RIRO in the same category as a crossover.

Left turns on a freeway?  Especially at one with a 70 mph or more speed limit?  No way would I consider that to be a freeway.

[NE2]

Left turns on a freeway?  Especially at one with a 70 mph or more speed limit?  No way would I consider that to be a freeway.

Good to know. I'll remember that next time someone asks me what Beltway's definition of a freeway is.

[Beltway]

Left turns on a freeway?  Especially at one with a 70 mph or more speed limit?  No way would I consider that to be a freeway.

Good to know. I'll remember that next time someone asks me what Beltway's definition of a freeway is.

I was trying not to be pushy, like saying that the highway engineering definition of freeway in the USA, would say the same.

[kphoger]

The definition of 'freeway' in the USA would not include a highway with a crossover open to the public, as that would be an at-grade intersection.

Maybe, maybe not.  I've never read of crossovers being a deal breaker for the term 'freeway' during my time on roads forums (which is not 15 years).  I suppose that's because I've never heard of a crossover referred to as an intersection before.

I don't see how it is possible to generalize about highway designs all over the world.  There is great variation in how things are done.

What you cited as "common knowledge"... I have been reading roads forums for 15 years, and that is the first such comments that I have seen.

Yes, there is great variation in how things are done.  That's sort of my point, isn't it?  Some countries restrict movement on freeways more, some less.  Some are more fond of grade separation, while others are more fond of crossovers.

I should not have assumed that to be common knowledge.  I've probably spent more time on foreign-country skyscrapercity roads forums than most, and have probably spent more time perusing foreign-country Google Maps satellite imagery than most.

Left turns on a freeway?  Especially at one with a 70 mph or more speed limit?  No way would I consider that to be a freeway.

Good to know. I'll remember that next time someone asks me what Beltway's definition of a freeway is.

Not all left turns are created equal.  I had posted an example of a crossover where traffic actually crosses the opposing lanes and then merges on the right; this would probably violate most people's definitions of a freeway.  But one where a car simply makes a U-turn in the median isn't exactly the same thing as a left turn, since there is no actual crossing of vehicle paths; were there proper accel/decel room, turning around at a location like this one in El Salvador would be no different than doing so on westbound I-10/I-20 in Texas.  The turning radius is smaller, but that's about it.

[kphoger]

highway engineering definition of freeway in the USA ^{[citation needed]}

[NE2]

I was trying not to be pushy, like saying that the highway engineering definition of freeway in the USA, would say the same.

I'm not sure I agree with you on that. For example this is on the 905 near San Diego: http://www.flickr.com/photos/navymailman/3768457776/in/photostream/
It's rather slow-speed, but it still qualifies as a freeway.

[Beltway]

The definition of 'freeway' in the USA would not include a highway with a crossover open to the public, as that would be an at-grade intersection.

Maybe, maybe not.  I've never read of crossovers being a deal breaker for the term 'freeway' during my time on roads forums (which is not 15 years).  I suppose that's because I've never heard of a crossover referred to as an intersection before.

Left turns -would- be a deal breaker.

You mentioned "U-turn in the median" in your post; other than for emergency and/or official use, there's no reason for that on a freeway.  The only call for a crossover open to public use would be to access an intersecting road.

[Beltway]

I was trying not to be pushy, like saying that the highway engineering definition of freeway in the USA, would say the same.

I'm not sure I agree with you on that. For example this is on the 905 near San Diego: http://www.flickr.com/photos/navymailman/3768457776/in/photostream/
It's rather slow-speed, but it still qualifies as a freeway.

It says --
U TURN TO USA

-- That doesn't make it a freeway.  It also seems to be a sign error, if indeed it is located in the USA.

[NE2]

That doesn't make it a freeway. Caltrans makes it a freeway.

[kphoger]

You mentioned "U-turn in the median" in your post; other than for emergency and/or official use, there's no reason for that on a freeway.  The only call for a crossover open to public use would be to access an intersecting road.

A quickly drawn illustration of a three-way highway interchange to show how that's not necessarily the case:


As you can imagine, this is quite a bit cheaper than building a trumpet interchange.  There are no conflicting movements other than merges and lane changes, and controlled access can still be maintained.

[Beltway]

That doesn't make it a freeway. Caltrans makes it a freeway.

Where does CalTrans say that that is a freeway?

[Beltway]

You mentioned "U-turn in the median" in your post; other than for emergency and/or official use, there's no reason for that on a freeway.  The only call for a crossover open to public use would be to access an intersecting road.

A quickly drawn illustration of a three-way highway interchange to show how that's not necessarily the case:


As you can imagine, this is quite a bit cheaper than building a trumpet interchange.  There are no conflicting movements other than merges and lane changes, and controlled access can still be maintained.

I can't imagine why a design like that would exist on what would otherwise be a freeway.

Slow down in left lane, enter decell lane, make u-turn, enter accell lane, speed up, weave across 2 lanes, enter decell lane, turn right.  Very un-freeway-like.

[NE2]

That doesn't make it a freeway. Caltrans makes it a freeway.

Where does CalTrans say that that is a freeway?

All over the place.
http://maps.google.com/maps?hl=en&ll=32.554491,-116.941266&spn=0.008247,0.016512&gl=us&t=k&z=17&layer=c&cbll=32.554552,-116.941147&panoid=VRnfNqKemY_s3BG6fTa_Mg&cbp=12,130.81,,1,6.23
http://maps.google.com/maps?hl=en&ll=32.555848,-116.939249&spn=0.008247,0.016512&gl=us&t=k&z=17&layer=c&cbll=32.5558,-116.939335&panoid=hkoUEF_aeO-xrL5hoOZD1Q&cbp=12,267.07,,0,15.2
And here's the U-turn itself:
http://maps.google.com/maps?hl=en&ll=32.55318,-116.939099&spn=0.004142,0.008256&gl=us&t=k&z=18&layer=c&cbll=32.552672,-116.939012&panoid=qOso0QREhsy8zmpPROKhJg&cbp=12,156.51,,0,9.01

[Beltway]

That doesn't make it a freeway. Caltrans makes it a freeway.

Where does CalTrans say that that is a freeway?

All over the place.
http://maps.google.com/maps?hl=en&ll=32.554491,-116.941266&spn=0.008247,0.016512&gl=us&t=k&z=17&layer=c&cbll=32.554552,-116.941147&panoid=VRnfNqKemY_s3BG6fTa_Mg&cbp=12,130.81,,1,6.23
http://maps.google.com/maps?hl=en&ll=32.555848,-116.939249&spn=0.008247,0.016512&gl=us&t=k&z=17&layer=c&cbll=32.5558,-116.939335&panoid=hkoUEF_aeO-xrL5hoOZD1Q&cbp=12,267.07,,0,15.2
And here's the U-turn itself:
http://maps.google.com/maps?hl=en&ll=32.55318,-116.939099&spn=0.004142,0.008256&gl=us&t=k&z=18&layer=c&cbll=32.552672,-116.939012&panoid=qOso0QREhsy8zmpPROKhJg&cbp=12,156.51,,0,9.01

But does CalTrans consider that one spot with the u-turn to be freeway-standard?

Besides, like I said, the sign message is self-contradictory.  If you are in the USA, you don't make a u-turn into the USA.

[kphoger]

You mentioned "U-turn in the median" in your post; other than for emergency and/or official use, there's no reason for that on a freeway.  The only call for a crossover open to public use would be to access an intersecting road.

A quickly drawn illustration of a three-way highway interchange to show how that's not necessarily the case:


As you can imagine, this is quite a bit cheaper than building a trumpet interchange.  There are no conflicting movements other than merges and lane changes, and controlled access can still be maintained.

I can't imagine why a design like that would exist on what would otherwise be a freeway.

Slow down in left lane, enter decell lane, make u-turn, enter accell lane, speed up, weave across 2 lanes, enter decell lane, turn right.  Very un-freeway-like.

As you can imagine, this is quite a bit cheaper than building a trumpet interchange.

And still somewhat similar to the I-10/I-20 example I cited above.

[Beltway]

You mentioned "U-turn in the median" in your post; other than for emergency and/or official use, there's no reason for that on a freeway.  The only call for a crossover open to public use would be to access an intersecting road.

A quickly drawn illustration of a three-way highway interchange to show how that's not necessarily the case:


As you can imagine, this is quite a bit cheaper than building a trumpet interchange.  There are no conflicting movements other than merges and lane changes, and controlled access can still be maintained.

I can't imagine why a design like that would exist on what would otherwise be a freeway.

Slow down in left lane, enter decell lane, make u-turn, enter accell lane, speed up, weave across 2 lanes, enter decell lane, turn right.  Very un-freeway-like.

As you can imagine, this is quite a bit cheaper than building a trumpet interchange.

And still somewhat similar to the I-10/I-20 example I cited above.

A freeway should be built to freeway standards, not with grossly substandard features to "save money".  IOW, build a bridge and ramps there.

The I-10/I-20 interchange is a true freeway.  The left-exit to left-entrance ramp is freeway-standard, even if today considered an obsolete design.

[NE2]

That doesn't make it a freeway. Caltrans makes it a freeway.

Where does CalTrans say that that is a freeway?

All over the place.
http://maps.google.com/maps?hl=en&ll=32.554491,-116.941266&spn=0.008247,0.016512&gl=us&t=k&z=17&layer=c&cbll=32.554552,-116.941147&panoid=VRnfNqKemY_s3BG6fTa_Mg&cbp=12,130.81,,1,6.23
http://maps.google.com/maps?hl=en&ll=32.555848,-116.939249&spn=0.008247,0.016512&gl=us&t=k&z=17&layer=c&cbll=32.5558,-116.939335&panoid=hkoUEF_aeO-xrL5hoOZD1Q&cbp=12,267.07,,0,15.2
And here's the U-turn itself:
http://maps.google.com/maps?hl=en&ll=32.55318,-116.939099&spn=0.004142,0.008256&gl=us&t=k&z=18&layer=c&cbll=32.552672,-116.939012&panoid=qOso0QREhsy8zmpPROKhJg&cbp=12,156.51,,0,9.01

But does CalTrans consider that one spot with the u-turn to be freeway-standard?

There's no 'end freeway' sign before it, so yes.

[kphoger]

Besides, like I said, the sign message is self-contradictory.  If you are in the USA, you don't make a u-turn into the USA.

Just consider yourself to be in the frontier zone at that point–No man's land–having left the USA but not yet arrived at México.  Such signage is common; nearby on I-5, you can find this.

A freeway should be built to freeway standards, not with grossly substandard features to "save money".  IOW, build a bridge and ramps there.

What is non-freeway about it?  What constitutes 'freeway standards' other than being free of cross traffic and stops?  A highway can be a freeway without conforming to Interstate standards, if that's what you're assuming 'freeway standards' to mean.

Slow down in left lane, enter decel lane, make U turn, enter accel lane, speed up, weave across two lanes one lane..... This is the correct procedure to get from WB I-20 to EB I-10–which is apparently 'freeway-standard'.  Add an option lane to my illustration, spread the median a bit, and flare the ramp from freeway to surface highway, and there's realistically no difference at all.

[Beltway]

That doesn't make it a freeway. Caltrans makes it a freeway.

Where does CalTrans say that that is a freeway?

All over the place.
http://maps.google.com/maps?hl=en&ll=32.554491,-116.941266&spn=0.008247,0.016512&gl=us&t=k&z=17&layer=c&cbll=32.554552,-116.941147&panoid=VRnfNqKemY_s3BG6fTa_Mg&cbp=12,130.81,,1,6.23
http://maps.google.com/maps?hl=en&ll=32.555848,-116.939249&spn=0.008247,0.016512&gl=us&t=k&z=17&layer=c&cbll=32.5558,-116.939335&panoid=hkoUEF_aeO-xrL5hoOZD1Q&cbp=12,267.07,,0,15.2
And here's the U-turn itself:
http://maps.google.com/maps?hl=en&ll=32.55318,-116.939099&spn=0.004142,0.008256&gl=us&t=k&z=18&layer=c&cbll=32.552672,-116.939012&panoid=qOso0QREhsy8zmpPROKhJg&cbp=12,156.51,,0,9.01

But does CalTrans consider that one spot with the u-turn to be freeway-standard?

There's no 'end freeway' sign before it, so yes.

Why did you snip the following?  It puts the whole installation in doubt, that someone there screwed up.

"Besides, like I said, the sign message is self-contradictory.  If you are in the USA, you don't make a u-turn into the USA."

[NE2]

I snipped it because it's off-topic. You're arguing like a Repub-a-dub-dub.