Exit tab with advance-exit-list sign

[TheStranger]

Not sure I've seen this setup before - anywhere.

From I-405 at Exit 1 (Route 133) in Irvine:


DSC_5959 by csampang, on Flickr

It seems like it's somewhat confusing, as I don't think the second listed exit is part of Exit 2 at all, but entirely what comprises Exit 3.

[agentsteel53]

indeed, it doesn't make any sense.  it's just Caltrans being stupid in their obedience of the "exit tabs! everywhere! now!" requirement.

[TheStranger]

indeed, it doesn't make any sense.  it's just Caltrans being stupid in their obedience of the "exit tabs! everywhere! now!" requirement.

I would like it IF Exit 3 was mentioned specifically for the lower exit in similar fashion.  Having said that, isn't there a risk for message overload with a sign like this?

[myosh_tino]

Not sure I've seen this setup before - anywhere.

From I-405 at Exit 1 (Route 133) in Irvine:


DSC_5959 by csampang, on Flickr

It seems like it's somewhat confusing, as I don't think the second listed exit is part of Exit 2 at all, but entirely what comprises Exit 3.

I'm thinking that has to be a sign goof.  Taking a closer look at the photo, it appears the original sign was altered because the "3/4" and the exit tab looks like it was pasted on.

[vdeane]

indeed, it doesn't make any sense.  it's just Caltrans being stupid in their obedience of the "exit tabs! everywhere! now!" requirement.

I would like it IF Exit 3 was mentioned specifically for the lower exit in similar fashion.  Having said that, isn't there a risk for message overload with a sign like this?

Cramming too much stuff into a sign is the very definition of CalTrans signage.

[SignBridge]

My guess is this was an error. The Manual doesn't require exit tabs on interchange sequence signs. I don't think the problem is quantity of legend on California signs as much as it is the hodgepodge way they arrange it sometimes. Like they threw darts at a board when formatting them. Though I have seen cases where they cram more legend on a sign panel than the size of the panel would reasonably allow. Maybe that's what the above poster meant.

If you want to see a state with excessive legend on their signs, go to New Jersey. Especially on I-80 between Paterson and the Geo. Washington Bridge. Other roads as well, where excessive route numbers and destinations are sometimes shown. 

[roadman]

My guess is this was an error. The Manual doesn't require exit tabs on interchange sequence signs. I don't think the problem is quantity of legend on California signs as much as it is the hodgepadge way they arrange it sometimes, way out of compliance with the Manual. Like they threw darts at a board when formatting them. Though I have seen cases where they cram more legend on a sign panel than the size of the panel would reasonably allow.

CalTrans seems to have the mindset of replacing 40 and 50 year old signs while still retaining the 40 and 50 year old support structures those signs are mounted to.  If the goal is to update legends without exceeding the original panel dimensions, it can explain many of the 'hodgepodge' legend formats CalTrans has come up with during recent sign replacement projects.

I've also heard rumors that separate exit tabs weren't provided on the new signs because it apparently would trigger an environmental review - presumably because of the additional 'shadow' effect the exit tab would create.

[myosh_tino]

CalTrans seems to have the mindset of replacing 40 and 50 year old signs while still retaining the 40 and 50 year old support structures those signs are mounted to.  If the goal is to update legends without exceeding the original panel dimensions, it can explain many of the 'hodgepodge' legend formats CalTrans has come up with during recent sign replacement projects.

If the 40-50 year old support structures are still structurally sound, why should they be replaced and add to the cost of a project?  Besides, I think sign panel height may play more of a role in the odd layout of signs when incorporating an exit number.

I've also heard rumors that separate exit tabs weren't provided on the new signs because it apparently would trigger an environmental review - presumably because of the additional 'shadow' effect the exit tab would create.

Never heard that used as an excuse.  I'm not saying it's inaccurate, just that I've never heard that separate tabs would require an environmental review.

[architect77]

I noticed in SF last month that new overheads had the exit tab above the main sign, however blank green is extended to the left of the exit tab to keep the sign itself merely a normal rectangle. I wondered if it was a wind issue or an aesthetic one: perhaps CalTrans just thinks an extra piece of metal above the main sign is ugly. All in all, I thought the signs still looked pretty good.

[SignBridge]

On the Pacific Southwest forum they're having a big discussion about separate exit number tabs. The consensus is that it's a wind-load issue, and also that Caltrans doesn't want to be bothered with extra mounting hardware.

[myosh_tino]

From the "California Observations" topic on the Pacific Southwest board...

The Caltrans sign truss standards were significantly revised in early 2005.  At that time, it was noted that the new structures could accommodate exit number tabs.  However, to this day, there has not been a detail made available for mounting tabs.  I have spoken with the engineer who is responsible for the sign structure standard plans, and he has told me that he knows there is a need for such a detail, but it is not a high priority.

So, yes the current Caltrans design is due to wind-loading... the new sign bridges can accommodate external exit tabs but no one has developed a method of mounting the external tabs and it's not a high priority.  IOW, don't expect to see external tabs on overhead signs in California anytime soon.  

[Central Avenue]

Besides, I think sign panel height may play more of a role in the odd layout of signs when incorporating an exit number.

This may be slightly off-topic, but...I've seen Caltrans's limited sign panel height requirements cited as the reason for some of their "quirky" design elements (like internal exit tabs), but I never understood why limited sign heights are necessary or desirable, especially when most other states get by fine with their taller signs. Am I missing something really obvious?

[Alps]

I would imagine the idea of maintaining sign height on existing structures to avoid having to do a new set of calculations and potentially replacing them is worthwhile enough to design around, to CalTrans. That said, I'm okay with blank space to the left of the exit tab, but not like shown in the original photo. When a sign is that cluttered, you completely lose the exit number information among the other text.

[roadfro]

This interchange sequence sign should not have an exit tab, plain and simple.

CalTrans' internal exit tabs don't really give me issue either...at least they are numbering exits now...

I like CalTrans' approach of similar-height signs on overhead structures...NDOT does the same thing. I accept the fact that replacing signs in the same size is smart from the engineering standpoint of not having to do new calcs. I think CalTrans' wind loading specs in certain instances are on the very conservative side, since NDOT uses some similar sign structures with exit tabs for years and has had no issues. They should make the tab detail a higher priority--reducing sign legend to fit the tab isn't the right approach...they should be putting on tabs wherever possible.

[J N Winkler]

I would imagine the idea of maintaining sign height on existing structures to avoid having to do a new set of calculations and potentially replacing them is worthwhile enough to design around, to CalTrans.

I don't think they are bothered about the calculations, but in the late 1980's District 7 and Headquarters collaborated on a freeway guide sign design handbook which mentioned the accumulation of old sign structures in maintenance yards statewide as a headache to be avoided.  I think Caltrans just likes to reuse whenever possible.

To comment on Roadman's suggestion that avoidance of environmental review might be another reason for using flush tabs, I think I have heard similar rumors myself.  I have never been sure how much credit to assign such suggestions, but I do know that assessment of visual impact is part of Caltrans' standard procedure for environmental impact statements.

[roadman]

I would imagine the idea of maintaining sign height on existing structures to avoid having to do a new set of calculations and potentially replacing them is worthwhile enough to design around, to CalTrans.

I don't think they are bothered about the calculations, but in the late 1980's District 7 and Headquarters collaborated on a freeway guide sign design handbook which mentioned the accumulation of old sign structures in maintenance yards statewide as a headache to be avoided.  I think Caltrans just likes to reuse whenever possible.

When MassDOT replaces sign support structures, which is usually every other cycle of sign replacement (or 35 to 40 years), the old supports are removed and discarded by the Contractor.  This results in lower bid prices for the new supports, as the Contractor will figure the scrap value of the old supports in their bid.

And, with due respect to CalTrans sign engineers, I reiteriate my earlier concerns about CalTrans practice of mounting new signs on 40 year old support structures.  I find it hard to believe these supports were so overbuilt in the first place that they meet current AASHTO design and wind loading standards.

[agentsteel53]

I find it hard to believe these supports were so overbuilt in the first place that they meet current AASHTO design and wind loading standards.

they probably did.  they certainly overbuilt the signs themselves; the porcelain signs from the 50s and 60s which were never retrofitted with grime-attracting reflective buttons are as shiny as they day they were installed. 

[myosh_tino]

they probably did.  they certainly overbuilt the signs themselves; the porcelain signs from the 50s and 60s which were never retrofitted with grime-attracting reflective buttons are as shiny as they day they were installed.  

Here's a good example of what Agentsteel53 is talking about.  The greenout panel on the bottom portion of the sign fell off to reveal an old action message "EXIT (arrow) 3/4 MI".  The portion that's visible was unreflectorized legend on a porcelain sign panel.

[agentsteel53]

Here's a good example of what Agentsteel53 is talking about.  The greenout panel on the bottom portion of the sign fell off to reveal an old action message "EXIT (arrow) 3/4 MI".  The portion that's visible was unreflectorized legend on a porcelain sign panel.

I need to find a good photo of this gantry, which has been exposed fully to the elements since 1968 and is in very good condition.  They just forgot to retrofit it in the 70s.

http://g.co/maps/nbmpp

for a better picture of a different example... this sign is from 1947 and is in active service. 

[myosh_tino]

Full Size Image from AARoads Gallery.

Here's another example of non-reflectorized legend on a porcelain guide sign.  IIRC, that the EXIT 3/4 MILE (arrow) message was never covered up and you can see the difference in clarity between the it and the reflectorized legend.

[J N Winkler]

When MassDOT replaces sign support structures, which is usually every other cycle of sign replacement (or 35 to 40 years), the old supports are removed and discarded by the Contractor.  This results in lower bid prices for the new supports, as the Contractor will figure the scrap value of the old supports in their bid.

But is it really usual to replace structures as well as sign panels?  My experience of the vast majority of state DOTs is that normal practice is to replace panels in pure signing contracts, leaving the existing structures alone (except in isolated cases)--MassDOT is actually the major exception to this rule I am aware of.  Most other states tend to combine sign structure replacement with full-depth roadway reconstruction.

[roadman]

I find it hard to believe these supports were so overbuilt in the first place that they meet current AASHTO design and wind loading standards.

they probably did.  they certainly overbuilt the signs themselves; the porcelain signs from the 50s and 60s which were never retrofitted with grime-attracting reflective buttons are as shiny as they day they were installed. 

The Massachusetts Turnpike had a number of these signs that were replaced as part of the 1995 signing project. They were supplied by a company called Cameo that fabricated the majority of the CalTrans porcelain signs - I have an old salesman's sample and related literature from 1968 in my office.

[Scott5114]

I find it hard to believe these supports were so overbuilt in the first place that they meet current AASHTO design and wind loading standards.

they probably did.  they certainly overbuilt the signs themselves; the porcelain signs from the 50s and 60s which were never retrofitted with grime-attracting reflective buttons are as shiny as they day they were installed. 

The Massachusetts Turnpike had a number of these signs that were replaced as part of the 1995 signing project. They were supplied by a company called Cameo that fabricated the majority of the CalTrans porcelain signs - I have an old salesman's sample and related literature from 1968 in my office.

What's the sample like? Is it interesting enough to post a picture of?

[agentsteel53]

They were supplied by a company called Cameo that fabricated the majority of the CalTrans porcelain signs - I have an old salesman's sample and related literature from 1968 in my office.

I would be very interested in seeing these!

I don't remember the Mass Pike having porcelain signs.  Anyone have any pictures?  I'll bet they said something like "CA-68" on the back.  There are some signs in Reno which say CA-78!

[SignBridge]

I'm confused about something. Are you guys saying that Caltrans' (white on dark-green) overhead signs from the 1960's did not originally have reflector-buttons on the lettering and borders? That the buttons were retrofitted later? Was the original lettering non-reflective? Or did they use reflective lettering material? That would be very surprising to me as a New Yorker, because NYSDOT's signs had buttons starting in about 1960 and continuing thru 1984 installations. I remember being very impressed with that new modern signing as a kid.