Interesting new California style of freeway junction exit number signing

[Michael]

I saw this thread in the "Info Center" at the bottom of the forum homepage.  I rarely venture out of the Northeast region, but this thread looked interesting enough to comment on.

I fail to see why California hates real exit tabs.  I looked up how big they have to be, and found that they add 30 inches to a sign assembly's height according to Table 2E-1 in the MUTCD (Page 186).  I would think that if wind loads were as severe of a problem as Caltrans claims, the tab would just break away in high winds.

As proof of the wind load on tall signs argument being a moot point, take this example from here in Upstate NY.  It survived the Labor Day storm of 1998, and is located about 4.5 miles from the State Fairgrounds, where a tornado touched down.  Based on the NYSDOT mounting requirement of 18 feet for this overhead sign (17 foot overpasses for the Interstate, plus 1 foot over the minimum bridge height, see this page for overhead sign design details) and the fact that it looks to be as tall as the space from the road surface to the bottom of the sign, I'd say that it's at least 18 feet high.  According to this PDF, the maximum height for an overhead sign is 19' 6".

Many California signs I've seen could have a much better layout if the exit number had an actual tab and/or the sign height were increased to add as little as one line of text as opposed to being squeezed in the sign.

P.S.: The word "for­um" (yay for invisible characters!) changed to "Usenet" in the preview.  Is that some April Fools joke?

[KEK Inc.]

Here's another center-tabbed oddity. 


Oh, and apparently there are some newer external tabs in California...






(Image Sources:  RaymondYu's Flickr)

[JustDrive]

Whoa, they changed the street name?  I remember it being just "Cabazon" not too long ago.

[Brandon]

Gee, those three photos show that the CalTrans wind-loading argument is full of hot air and bullshit.

[J N Winkler]

Oh, and apparently there are some newer external tabs in California...

This is unusual because it is an external tab adjacent to the RSPF for a formed-panel sign.

These are all laminated-panel signs.

[J N Winkler]

I fail to see why California hates real exit tabs.  I looked up how big they have to be, and found that they add 30 inches to a sign assembly's height according to Table 2E-1 in the MUTCD (Page 186).

Actually, 24" is the standard tab height in California.

It is not a question of Caltrans "hating" exit tabs.  The sign specs all present strip tabs, external tabs, and bitten-out tabs as allowable design options, and all three have been used in California.  I think the relative unpopularity of external tabs (particularly on overhead signs, which are the reason KEK's pictures are of interest) has more to do with the lack of standard mounting details for trusses and for some types of sign substrate that Caltrans frequently uses.  Caltrans is understaffed as it is, so if some form of "inside" tab complies with the standards and does not require an added detail to be drawn up and verified separately, then it is an instant winner in terms of preparation time.  I suspect the pictures KEK posted are all taken from OSFP work designed by consultants working for regional measure agencies, county engineering departments, and even Indian tribes (the Morongo sign, I am 99% sure, was funded by the Morongo reservation as part of their casino development).

I would think that if wind loads were as severe of a problem as Caltrans claims, the tab would just break away in high winds.

Even a 24" tab flying around in a high wind is dangerous.  That said, I don't think the wind loading argument works against exit tabs in quite that way.  I think it has more to do with a replacement sign fitting within the same footprint as the existing sign not needing calculations to verify that it complies with wind loading standards, while a sign with an external tab would not fit into the same area and would need wind loading calculations to be done.

P.S.: The word "for­um" (yay for invisible characters!) changed to "Usenet" in the preview.  Is that some April Fools joke?

Yes, a rather annoying one, which now has fortunately ended.

[Alps]

P.S.: The word "for­um" (yay for invisible characters!) changed to "Usenet" in the preview.  Is that some April Fools joke?

Yes, a rather annoying one, which now has fortunately ended.

Someone needs a sense of humor installed.

[J N Winkler]

Someone needs a sense of humor installed.

I'd certainly agree with that.

[Alps]

Someone needs a sense of humor installed.

I'd certainly agree with that.

Congrats on your shortest post ever!

[KEK Inc.]

The Oregon signs were proved to be fake, so it's probable the external tab photos that I posted could be fake.

[Interstate Trav]

Am I the only one that likes the I-710 Exit sign at the 60?  It seems less confusing to me then a lot of other signs, that get almost no complaints.  Also just curiuosity why does Caltrans always get put down so much in this forum, not that I'm defending Caltrans.  Just wondering.

[The High Plains Traveler]

Here's another center-tabbed oddity. 

I actually find this layout to be informative. It tells me that both identified routes (I-10 East and West) exit the mainline at this point, and the ramp will divide shortly after the exit. The exit tab ties the two together and I would not infer the possibility of a second exit for WB I-10 just ahead. Now, if California had used the upper-right pointing arrows rather than the down arrows at the exit point, it would tell me much the same thing.

[blawp]

Those external tab pictures are absolutely fake. I drive the 10, 60, and 210 routinely and have never seen those.

[PurdueBill]

I did see one external tab sign on I-5 SB heading towards San Diego two weeks ago today; I wish I'd taken a picture so I could remember where.  That was the only such one I noticed anywhere between LA and SD, taking 405 and 5 all the way from near LAX down to the last exit before Mexico.  Not sure why that one sign had a tab--error, contractor decision, who knows.

[ARMOURERERIC]

There are/were a set of signs with external tabs on i-5 just south of the 101 junction but before the 710, they have been there a very long time.

[vdeane]

Those external tab pictures are absolutely fake. I drive the 10, 60, and 210 routinely and have never seen those.

Thought they looked too good to be true.

[TheStranger]

There are/were a set of signs with external tabs on i-5 just south of the 101 junction but before the 710, they have been there a very long time.

Those (as well as external tabs along the US 101 segment of the Santa Ana Freeway, and the 110 Harbor Freeway) all date back to a 1971 signing experiment.  IIRC, the first 30 miles of I-10 were a part of this as well, though most of the 1971-era signs along that route have been replaced over time.

[Brandon]

There are/were a set of signs with external tabs on i-5 just south of the 101 junction but before the 710, they have been there a very long time.

Those (as well as external tabs along the US 101 segment of the Santa Ana Freeway, and the 110 Harbor Freeway) all date back to a 1971 signing experiment.  IIRC, the first 30 miles of I-10 were a part of this as well, though most of the 1971-era signs along that route have been replaced over time.

If external tabs could be used in 1971, why not currently?  Many of the CalTrans gantries haven't changed since then, design-wise.

[vdeane]

Probably because the 1971 experiment was voluntary, and the current numbers were forced by the FHWA.

[pctech]

Here in Louisiana we have external exit# tabs and we have hurricanes force wind as well. I guess that LADODT doesn't consider it an issue. I've never seen one blow off, but that doesn't mean it couldn't happen. That said I don't mind the Caltrans  embedded exit# tab. I would prefer it on the right or left edge of the sign however and I agree that the exit should have up facing arrows.
They just put up new signs alone I-12 after widening it. One of them has a Caltrans look to it at the exit, but not at the interval warning sign.

Mark

[bulkyorled]

Whoa, they changed the street name?  I remember it being just "Cabazon" not too long ago.

It's always been been Morongo Trail, the sign use to say Cabazon because it was the city at that exit. Morongo Trail is basically just the 2 roundabouts at the freeway exit (or maybe just 1 since theres a sign that says Apache Trail but I cant figure out where that is) The exit clearly serves Seminole Dr

[Interstatefan78]

Going back to TheStranger's original post, yeah, that centered tab within the sign looks weird.  If I were the sign designed, here's what I would have suggested.

The original...


Suggestion #1...


Suggestion #2...

There should be another freeway that uses these same sign designs it's the 405 freeway (San Diego Freeway) at the 101 freeway (Ventura Freeway) in Sherman Oaks they were installed this April when I drove from LAX up to the Ventura area.

[pctech]

I prefer the middle design. (one exit number tab)

Mark

[Interstatefan78]

I prefer the middle design. (one exit number tab)

Mark

But the center tabbed seems to be good considering that it can take less sign making effort  than a split tabbed design which is suggestion #2

[pctech]

In the case of a left handed exit. The tab is on the left side of the sign and there is a yellow/black lettering "left exit" block in the main body of the sign? At least this is what I've seen on the few pictures of left exits that I've seen in CA. Here the the entire exit tab is yellow with black lettering now.

Mark