California Observations

[J N Winkler]

The figure I remember is a little over five thousand.

[florida]

The only exciting observation I've found so far (besides button-copy) is the Millbrae exit on US 101 is signed with two different numbers. Exit 420 for SB and 421 for NB.

And it's amusing to find a very tiny amount of doghouses out here.

[myosh_tino]

The only exciting observation I've found so far (besides button-copy) is the Millbrae exit on US 101 is signed with two different numbers. Exit 420 for SB and 421 for NB.

And it's amusing to find a very tiny amount of doghouses out here.

Yeah, that's actually a sign goof (but a good catch... I never noticed that before and I drive that section of US 101 somewhat regularly too).  The Millbrae Avenue exit is exit 420 per the Caltrans website.

You won't find too many doghouse signals out here.  Cities would rather have dedicated left-turn signals on the mast arms instead of installing the combo doghouse signals.  Also, as some have pointed out, almost all left turns are protected here in California.  Permissive left turns are generally allowed where there isn't a protected left.  In most cases, the signal will just show a green ball indicating all movements (left, straight, right) are permitted.

[Bickendan]

I thought I've noticed a few interchanges with two different exit numbers, because one of the ramps fell within the next exit number's range.

[agentsteel53]

The only exciting observation I've found so far (besides button-copy) is the Millbrae exit on US 101 is signed with two different numbers. Exit 420 for SB and 421 for NB.

And it's amusing to find a very tiny amount of doghouses out here.

I believe the "exit 420" tab is the only button copy exit tab on a retroreflective sign.  It might be a different exit number, but it is definitely in that range.  they cobbled together an exit tab using surplus button copy.

[nexus73]

The only exciting observation I've found so far (besides button-copy) is the Millbrae exit on US 101 is signed with two different numbers. Exit 420 for SB and 421 for NB.

And it's amusing to find a very tiny amount of doghouses out here.

CalTrans ran out of 420...LOL!

My best friend has a wife who drives a minivan with the plate being 421 DUD, which isn't as good as 420 BUD of course!

Rick

[myosh_tino]

I believe the "exit 420" tab is the only button copy exit tab on a retroreflective sign.  It might be a different exit number, but it is definitely in that range.  they cobbled together an exit tab using surplus button copy.

I believe this is the sign you are talking about...



While the exit "tab" is button copy, the sign itself is not retroreflective.

[kphoger]

I was looking at a video of I-80 through Donner pass recently. It's an astonishing beautiful drive! I know that Caltrans is rebuilding this entire section as the pavement was worn out.  I notice in the video (which is eastbound) that there warning signs for slippery when wet/frost on what appeared to be new concrete. Were there problems with new construction?

Mark

I think the "Slippery When Wet/Frost" signs are intended for the winter months when there is ice and snow in the area.  It doesn't matter if the pavement is new or 50 years old.

I once heard that Slippery When Wet signs are erected in locations that have a history of weather-related accidents.  Is that true?  At any rate, do they ever take them down?

[agentsteel53]

I believe this is the sign you are talking about...

nope.  It might be further north.  southbound, and the tab is a square - EXIT on one line, 4XX below it.  426 maybe? 

the main sign is definitely retroreflective.

[TheStranger]

I believe this is the sign you are talking about...

nope.  It might be further north.  southbound, and the tab is a square - EXIT on one line, 4XX below it.  426 maybe? 

the main sign is definitely retroreflective.

Are you thinking of Sierra Point Parkway exit off of 101, where the ramps are about a mile apart in each direction?

[pctech]

Does Caltrans "patch"(exit# tabs, arrows,etc) the BGS in order to save money? extend sign life? both?

Mark

[agentsteel53]

Are you thinking of Sierra Point Parkway exit off of 101, where the ramps are about a mile apart in each direction?

I honestly do not remember, other than that it is southbound, and in the northern reaches of Silicon Valley.

Mark pctech: to save money.

[myosh_tino]

I've been racking my brain trying to figure out what guide sign on southbound US 101 has a button copy exit "tab" on a reflective sign.  The only button copy exit tab I know of is the Millbrae Ave sign.  All signs on US 101 within San Mateo county (except for the Millbrae Ave sign) were replaced within the past 5 years or so with new reflective signs.

[pctech]

http://www.pressdemocrat.com/article/20110929/ARTICLES/110929401

I found this interesting. Here in Louisiana we allow permissive left turns, (yield on green ball) this might work here in congested urban areas.
I assume that the system uses the signal control cameras to determine that intersection is clear and activate the flashing yellow arrow mode.

Mark

[The High Plains Traveler]

http://www.pressdemocrat.com/article/20110929/ARTICLES/110929401

I found this interesting. Here in Louisiana we allow permissive left turns, (yield on green ball) this might work here in congested urban areas.
I assume that the system uses the signal control cameras to determine that intersection is clear and activate the flashing yellow arrow mode.

Mark

No. In FYA mode the yellow arrow will flash whenever oncoming traffic has a green. At a given intersection it's either full-time or is replaced with a protected-only mode during pre-programmed peak traffic periods.

[roadfro]

http://www.pressdemocrat.com/article/20110929/ARTICLES/110929401

I found this interesting. Here in Louisiana we allow permissive left turns, (yield on green ball) this might work here in congested urban areas.
I assume that the system uses the signal control cameras to determine that intersection is clear and activate the flashing yellow arrow mode.

Mark

The Traffic Control child board of General Highway Talk has a few threads discussing operation and purpose of flashing yellow arrows. You should check those out.

[pctech]

I've been watching a few more California video freeway videos.I noticed that in the S.F. bay area that some of the BGS signs  there have a "line" thru the top with the exit# tab in that surrounded by the typical CA. "number bubble". Are these unique to that part of the state? Is it up to each division of Calrans? I haven't seen them in videos of southern CA.  freeways.  Also noticed that as I-40 leaves CA. into AZ. there are "regular type" exit# tabs on the advanced approach signs for AZ. I thought Caltrans was worried about them blowing off in the wind?

Mark

[J N Winkler]

I've been watching a few more California video freeway videos.  I noticed that in the S.F. bay area that some of the BGS signs  there have a "line" thru the top with the exit# tab in that surrounded by the typical CA. "number bubble". Are these unique to that part of the state?

I think District 4 (which covers the SF Bay Area) is probably the only Caltrans district in which the "strip style" (which is what you describe) is used on overhead guide signs.  District 6 does use them for ground-mounted signs, such as near Tehachapi.

Is it up to each division of Caltrans?

It is up to the individual engineer.  Caltrans has sign specs covering all three tab styles (regular, bitten-out, strip).

Also noticed that as I-40 leaves CA. into AZ. there are "regular type" exit# tabs on the advanced approach signs for AZ. I thought Caltrans was worried about them blowing off in the wind?

Those signs (as well as the advance guide signs for Arizona exits on I-10 and I-8) are actually installed by Arizona DOT on California soil.  Caltrans agrees to allow them to design and fabricate them to their standards, and the ADOT construction plans include special details for California-specific elements such as the miner's spade shield.

Caltrans has used regular tabs on ground-mounted signs, especially as retrofits (as on I-5 near the Oregon state line), but for all-new sign panels the preferred solution is generally to use strip-style or bitten-out tabs.  Caltrans generally uses laminated panels instead of aluminum extrusions for ground-mounted guide signs, so attaching a regular exit tab means driving bolts through the front of the main sign panel instead of through extrusion flanges, since laminated panels are not pre-fabricated with mounting points for exit tabs.  Other state DOTs which use laminated panels, like PennDOT, have the same problem and use strip-style tabs just like Caltrans does.  (I think bitten-out tabs are unique to Caltrans, however.)

[myosh_tino]

Other state DOTs which use laminated panels, like PennDOT, have the same problem and use strip-style tabs just like Caltrans does.  (I think bitten-out tabs are unique to Caltrans, however.)

You forgot about this sign...

[CentralCAroadgeek]

I've seen the new 101 shields around Tully Road in San Jose, and I've noticed that the "NORTH" and "SOUTH" have the first letter in them raised, which really isn't that common in California.

[myosh_tino]

I've seen the new 101 shields around Tully Road in San Jose, and I've noticed that the "NORTH" and "SOUTH" have the first letter in them raised, which really isn't that common in California.

It's not common now but expect it to become common soon.  Caltrans updated their sign specs for the directional banners (i.e. NORTH, SOUTH, EAST, WEST... California sign codes G47, G48, G49 and G50) in January of 2012 to include the raised first letter.  I've seen these newer banners on the FREEWAY ENTRANCE assemblies at the on-ramp from Stevens Creek Blvd to I-280 northbound.

[J N Winkler]

It's not common now but expect it to become common soon.  Caltrans updated their sign specs for the directional banners (i.e. NORTH, SOUTH, EAST, WEST... California sign codes G47, G48, G49 and G50) in January of 2012 to include the raised first letter.  I've seen these newer banners on the FREEWAY ENTRANCE assemblies at the on-ramp from Stevens Creek Blvd to I-280 northbound.

I have been seeing the raised initial letter in cardinal direction words in recent Caltrans signing plans as well.  I haven't checked to see whether the G-series specs for large panel signs have been revised accordingly.

[pctech]

The Caltrans embedded exit# tab does save money on the signs I would imagine. There are a lot of freeway BGS in CA. I wonder how much a typical BGS cost and how much of the cost is the exit# tab?

Mark

[J N Winkler]

I don't think the bitten-out or strip-style tabs result in a cheaper sign panel.  If you have a separate exit tab, you pay just for sheeting plus substrate for a tab which is no wider than needed and for sheeting plus substrate for a main sign panel which is closely drawn around the legend.  This keeps your sheeting costs to a minimum.  Whether it keeps your substrate costs to a minimum depends on how much cheaper it is to use a form of substrate construction (such as laminated-panel or formed-panel) that requires that the entire sign message (main sign legend plus exit tab information) fit into a rectangular envelope.

My suspicion is that with newer microprismatic sheetings, the cost per unit area of the sheeting is now several times the cost per unit area of the substrate, whatever type of substrate is used.  Assuming that this is true, then I think the real reason Caltrans isn't chucking money out the window using strip-style and bitten-out tabs is that it is overcommitted to sign structures which require that the complete sign message be in a rectangular format.  This made economic sense decades ago when sign backgrounds were not retroreflectorized and sign panels had a typical service life of over 50 years, but standards have now changed and Caltrans has a problem of excess durability.

Keep in mind that Caltrans exit tabs are smaller than the MUTCD requires.  (The MUTCD calls for 30" tab height, with many states using 36" instead; 15" exit number; and 10" word "EXIT."  Caltrans uses 24" tab height, 12" exit number, and 8" word "EXIT.")  So Caltrans already relies on substandard provision to shave the cost.  TOPS circular 02-04, which I think is still in effect, also allows designers to reduce the letter height of the main sign panel legend when it is necessary to fit in an exit tab.

[myosh_tino]

Keep in mind that Caltrans exit tabs are smaller than the MUTCD requires.  (The MUTCD calls for 30" tab height, with many states using 36" instead; 15" exit number; and 10" word "EXIT."  Caltrans uses 24" tab height, 12" exit number, and 8" word "EXIT.")  So Caltrans already relies on substandard provision to shave the cost.  TOPS circular 02-04, which I think is still in effect, also allows designers to reduce the letter height of the main sign panel legend when it is necessary to fit in an exit tab.

That came as a surprise to me.  What other states, besides Arizona, use an exit tab larger than the MUTCD-specified 30 inches?  As for Caltrans allowing sign designers to use reduced letter heights on signs to fit in an exit tab, as far as I know, is still being allowed with the most common practice I've seen is using 13.33/10 letter heights for the main legend (reduced from 16/12).  Here's a photo someone posted in another thread of signs on I-5 near Stockton that appear to use reduced letter heights...