California needs diagram signs, really badly.

[Lytton]

So, yesterday, I was driving on US 101 south through Downtown LA, when all of a sudden. I had to get over to my right to get on US 101, since the left is I-10 East. What the fuck? There was no diagram sign beforehand, it was only on the next few exits with miles sign.

The only diagram sign I can find is when you are driving down the Coronado Bay Bridge East, and you see a sign for I-5 South and National Boulevard. Whenever I get to the I-805/I-5 split, in order to get on I-5, you have to get to the right immediately if you are on the left to avoid going on I-805. No diagram signs beforehand. Damn, I think that the Northeast USA is better than California, because...Why the fuck does California have no diagram signs for complicated interchanges.

Hey California, you wanna know why most road accidents happen near complicated interchanges. Because you don't have diagram signs so the drivers that don't know much about the LA area have to merge to the right, and it will cause a collision or just stop traffic altogether. Put some frickin' diagram signs, CalTrans. It's not that hard.

[sdmichael]

So, yesterday, I was driving on US 101 south through Downtown LA, when all of a sudden. I had to get over to my right to get on US 101, since the left is I-10 East. What the fuck? There was no diagram sign beforehand, it was only on the next few exits with miles sign.

The only diagram sign I can find is when you are driving down the Coronado Bay Bridge East, and you see a sign for I-5 South and National Boulevard. Whenever I get to the I-805/I-5 split, in order to get on I-5, you have to get to the right immediately if you are on the left to avoid going on I-805. No diagram signs beforehand. Damn, I think that the Northeast USA is better than California, because...Why the fuck does California have no diagram signs for complicated interchanges.

Hey California, you wanna know why most road accidents happen near complicated interchanges. Because you don't have diagram signs so the drivers that don't know much about the LA area have to merge to the right, and it will cause a collision or just stop traffic altogether. Put some frickin' diagram signs, CalTrans. It's not that hard.

The San Bernardino Split - US 101/I-10 (well, Route 10) is signed well enough for people to figure out that US 101 is on the right and I-10 is on the left. Pull through signs at a Y split aren't tough to figure. Some interchanges do have diagrams - EB 94 at 15, SB 15 at 215, WB Bus 80 at 50/99... There are plenty more around the state.

[Lytton]

Yes, but the I-805 and I-5 split for newcomers would be confusing for them. For one thing, they probably think that I-805 is on the right handside and is a flyover until they actually encounter the approach. Man, I wouldn't blame them though.

Put diagram signs on the complicated interchanges with a lot of cars traversing through that freeway. In fact, LA area should add more diagram signs.

[myosh_tino]

Yes, but the I-805 and I-5 split for newcomers would be confusing for them. For one thing, they probably think that I-805 is on the right handside and is a flyover until they actually encounter the approach. Man, I wouldn't blame them though.

Put diagram signs on the complicated interchanges with a lot of cars traversing through that freeway. In fact, LA area should add more diagram signs.

Doing a quick look at Google Maps, it looks like there are advance guide signs for the I-805 exit a good mile before the exit.  That should be plenty of time to determine which lane you need to be in.  Besides, big diagrammatic signs are being phased out in the 2009 MUTCD and being replaced with arrow-per-lane signs which kind of look like this...



This monstrocity, by my calculations, would be over 86.5 feet wide by 16.5 feet high.  That's over 1427 square feet!  This sign would never be fabricated in California because overhead guide signs cannot be more than 10 feet in height per current Caltrans standards.

[Alps]

Yes, but the I-805 and I-5 split for newcomers would be confusing for them. For one thing, they probably think that I-805 is on the right handside and is a flyover until they actually encounter the approach. Man, I wouldn't blame them though.

Put diagram signs on the complicated interchanges with a lot of cars traversing through that freeway. In fact, LA area should add more diagram signs.

Doing a quick look at Google Maps, it looks like there are advance guide signs for the I-805 exit a good mile before the exit.  That should be plenty of time to determine which lane you need to be in.  Besides, big diagrammatic signs are being phased out in the 2009 MUTCD and being replaced with arrow-per-lane signs which kind of look like this...



This monstrocity, by my calculations, would be over 86.5 feet wide by 16.5 feet high.  That's over 1427 square feet!  This sign would never be fabricated in California because overhead guide signs cannot be more than 10 feet in height per current Caltrans standards.

Demonstrating why these signs are ridiculous and why it is so critical to keep diagrammatics as an option.

[JustDrive]

The 5/805 split is signed for the first time at the Del Mar Heights Road overpass, which is about 3 miles north (there used to be an old button-copy sign saying that it was 5 1/4 miles from the Via de la Valle interchange).  Then once you pass the 56, you're bombarded with signs for the 805 split, and that's not including the bypass.  Add that to the fact that you have a full 2 miles between the 56 and the 805 with no exits on the mainline, and you should really have no confusion about which way the 805 splits from the 5.

[flowmotion]

In Northern California, advanced signage seems pretty minimal. You might get one or two secondary mileage signs and then all of a sudden it's "EXIT ONLY NOW 1/2 MILE!" and you'd better be close to the right lane.

Sometimes this is really nefarious, such as when mainline East I-80 suddenly exits near Sacramento. Or the southbound SFO exit, which is listed third on a generic sign with no lane markers.

In any case, I've witnessed numerous people miss their exits when in unfamiliar territory.  I've probably done it myself, but can't think of a specific occasion.

[myosh_tino]

In Northern California, advanced signage seems pretty minimal. You might get one or two secondary mileage signs and then all of a sudden it's "EXIT ONLY NOW 1/2 MILE!" and you'd better be close to the right lane.

Caltrans is getting a little bit better in urban areas where new exit direction signs will also have an advance guide sign for the next exit on the same gantry.  Otherwise, Caltrans is really good about installing interchange sequence signs that show the next 3 exits and the distances to said exits.  In rural areas you are pretty much out of luck except you will generally see an advance guide sign about a mile out.

Sometimes this is really nefarious, such as when mainline East I-80 suddenly exits near Sacramento.

Looks like you have 2 1/4 miles to make your way to the right lanes...

From the AARoads Gallery

Or the southbound SFO exit, which is listed third on a generic sign with no lane markers.

I'll give you that one although there are overhead signs for the airport with down arrows on the same gantries as the signs for the I-380/I-280 exits.  Looks like you have about 1/2 to 3/4 mile advance warning.

[pctech]

I like the arrow per lane type signs, think it's does a better job where freeways "splt" to multiple lanes.

[OCGuy81]

I could certainly see some benefit to diagrams for complicated interchanges, where traffic is exiting to the left, perhaps. 

Also, I think "the maze" in Oakland after taking 80 across the Bay Bridge would benefit from one.

Another alternative, if using mileage signs to a particular interchange is to put a yellow "Left Exit" box if the highway splits off to the left. 

[agentsteel53]

Whenever I get to the I-805/I-5 split, in order to get on I-5, you have to get to the right immediately if you are on the left to avoid going on I-805.

why are you in the left lane to begin with?

the general tone of your posts implies strongly that you're doing 50mph in said left lane.

[kphoger]

Yes, but the I-805 and I-5 split for newcomers would be confusing for them. For one thing, they probably think that I-805 is on the right handside and is a flyover until they actually encounter the approach. Man, I wouldn't blame them though.

Put diagram signs on the complicated interchanges with a lot of cars traversing through that freeway. In fact, LA area should add more diagram signs.

Doing a quick look at Google Maps, it looks like there are advance guide signs for the I-805 exit a good mile before the exit.  That should be plenty of time to determine which lane you need to be in.  Besides, big diagrammatic signs are being phased out in the 2009 MUTCD and being replaced with arrow-per-lane signs which kind of look like this...



This monstrocity, by my calculations, would be over 86.5 feet wide by 16.5 feet high.  That's over 1427 square feet!  This sign would never be fabricated in California because overhead guide signs cannot be more than 10 feet in height per current Caltrans standards.

Demonstrating why these signs are ridiculous and why it is so critical to keep diagrammatics as an option.

That sign would look a lot better without the yellow EXIT ONLY tabs.

[flowmotion]

Sometimes this is really nefarious, such as when mainline East I-80 suddenly exits near Sacramento.

Looks like you have 2 1/4 miles to make your way to the right lanes...

Double checking on google, there doesn't appear to be any I-80 BGSs between 2 1/4 and 1/2 mile from the exit. Which seems like an odd practice as you'd expect an advanced sign at say 1 mile distance. Perhaps it's because of the causeway.

[myosh_tino]

Perhaps it's because of the causeway.

I think you hit the nail on the head! 

[J N Winkler]

Going back to the I-5/I-805 El Cajon split, here are a couple of options for economizing on sign panel area:

[JustDrive]

Why would El Cajon be signed on 805 anyway?  Just asking.

[myosh_tino]

Why would El Cajon be signed on 805 anyway?  Just asking.

Since it was my drawing that introduced "El Cajon" as a control city for I-805, I chose El Cajon because from I-805, you can take I-8 or CA-52/CA-67 to reach El Cajon and I think it's a better route than following I-5 to I-8.

[agentsteel53]

do people actually go to El Cajon, though?

I live one town away from El Cajon and even I hardly ever go there.

[Henry]

Going back to the I-5/I-805 El Cajon split, here are a couple of options for economizing on sign panel area:

Not bad, but the classic diagram sign would be of most benefit, with a series of broken lines indicating the lanes that go through the split area. It always irks me when there are no broken lines in the diagrams (and quite a few examples are out there); with them, you get a better idea of whether to stay in your current lane or switch over well in advance of the actual split.

[roadfro]

Not bad, but the classic diagram sign would be of most benefit, with a series of broken lines indicating the lanes that go through the split area. It always irks me when there are no broken lines in the diagrams (and quite a few examples are out there); with them, you get a better idea of whether to stay in your current lane or switch over well in advance of the actual split.

I'd disagree in this case. When you get a diagrammatic arrow that has more than a few lanes in it, it becomes difficult to discern how many lanes there are in order to figure out where you need to be. These variations at least make it readily apparent that there are seven lanes on the approach and that the middle one is the option lane--it's a decent compromise to an arrow-per-lane sign.

[realjd]

Am I the only one who likes the large arrow-per-lane sign above? It makes it blindingly obvious which lane goes where, and isn't that the point of guide signs? I always hated complex diagrammatic signs since it can be hard to count the little dotted lines if there are more than two or three lanes.

[roadfro]

Oh, I like the APL signs for their clarity. I just have issue with the mammoth size of them. When you've got that many arrows and lanes with that little legend, it just seems like a big wast of space and money.

[mtantillo]

Oh, I like the APL signs for their clarity. I just have issue with the mammoth size of them. When you've got that many arrows and lanes with that little legend, it just seems like a big wast of space and money.

The point is to get the arrow over the applicable lane...thus the sign needs to be as wide as the road.  Now the mammoth height of the arrows....that I wish there was some more flexibility on. 

[roadfro]

Oh, I like the APL signs for their clarity. I just have issue with the mammoth size of them. When you've got that many arrows and lanes with that little legend, it just seems like a big wast of space and money.

The point is to get the arrow over the applicable lane...thus the sign needs to be as wide as the road.  Now the mammoth height of the arrows....that I wish there was some more flexibility on.

I realize this, but it gets extremely unwieldy when you get to 5 or more lanes, as the sign becomes a huge monster that doesn't seem like it's worth the expense...like no sign should be that big ever. (Note that the MUTCD does not provide any examples of an APL sign or other split with more than four lanes on the approach...) The images J N provided seem like they could make a good compromise and be more clear than existing diagrammatic arrows--slightly wider sign width than a diagrammatic arrow sign, but nowhere near the height required for an APL.

I agree that the height of the arrows on APL signs could probably be made slightly smaller to help reduce the overall sign height.