Maryland SHA using new style for diverging highways signage

[talllguy]

Greetings. Today I noticed that SHA had removed three separately posted shields at the point where northbound Interstate 83 diverges. Here is the new sign:

http://mapillary.com/map/im/CTQP8F1XT5p10xoxOCmaqA

Here is the old style, with three separate shields:

http://mapillary.com/map/im/7mknqyNCn-UiqUtGVxaoPw

What do folks think of the new BGS type sign with the shields, as opposed to the separate ones?

[NE2]

Haven't they been doing this for a while?

[talllguy]

Ah, I guess I should have said "new" at this location

[Don'tKnowYet]

I'm convinced that MdSHA has no idea that there are going to kill someone for no reason.  The physical gore is maybe the location on the freeway that is commonly the spot generally experiencing the most crashes.  Why anyone would put a sign like the "new way" in that high crash area is perplexing; especially a sign that is over fifty square feet--which is the magic number where a sign goes from possibly puncturing the windshield (under fifty) to crushing the passenger compartment (over fifty) if the breakaway support fails to perform in which it as designed.

If warranted at all, the point of any sign in the physical gore is for positive guidance.  The "old way" fulfills that purpose just fine and won't kill the passenger unless there is some freak crash with a convertible or something.  Crashing into a sign like those shown the "old way" is ike taking out a matchstick.

This sign (https://www.google.com/maps/@38.7991219,-77.0200063,3a,75y,175.64h,92.01t/data=!3m4!1e1!3m2!1sKl1yVjR1R04M45I2jLFPEg!2e0) was taken out last month and the little pick up truck that hit it and was on the back of the flatbed being towed away didn't do so well.  No logical reason why--when the primary message is adequately overhead at the theoretical gore for the departure movement--that MdSHA should be putting a giant sign over fifty square feet made of extruded aluminum in the nose of the physical gore. 

[jakeroot]

I'm convinced that MdSHA has no idea that there are going to kill someone for no reason.  The physical gore is maybe the location on the freeway that is commonly the spot generally experiencing the most crashes.  Why anyone would put a sign like the "new way" in that high crash area is perplexing; especially a sign that is over fifty square feet--which is the magic number where a sign goes from possibly puncturing the windshield (under fifty) to crushing the passenger compartment (over fifty) if the breakaway support fails to perform in which it as designed.

If warranted at all, the point of any sign in the physical gore is for positive guidance.  The "old way" fulfills that purpose just fine and won't kill the passenger unless there is some freak crash with a convertible or something.  Crashing into a sign like those shown the "old way" is ike taking out a matchstick.

Both signing options have their downsides:

[Don'tKnowYet]

Nice try.  Assuming the picture is real, rebar isn't used as a sign post. U- channel posts can't puncture a windshield that isn't already cracked. The sign that's posted on it could, but the post pretty much snaps/bends on impact.

[jakeroot]

Nice try.  Assuming the picture is real, rebar isn't used as a sign post. U- channel posts can't puncture a windshield that isn't already cracked. The sign that's posted on it could, but the post pretty much snaps/bends on impact.

It was meant as a joke; I can't think of any way a sign post could come through one's windscreen as such.

It is real:

AND WARNING, THIS IS NOT FOR THE FAINT OF HEART (for fucks sake please keep this in mind before hitting play -- this is really graphic with plenty of gore):

[BrynM65]

Out of interest have passively safe sign masts been introduced in the USA?  Highway designers here are obliged to consider their use in areas where a collision may occur.

[Don'tKnowYet]

Nice try.  Assuming the picture is real, rebar isn't used as a sign post. U- channel posts can't puncture a windshield that isn't already cracked. The sign that's posted on it could, but the post pretty much snaps/bends on impact.

It was meant as a joke.

i knew you were joking.

[talllguy]

Out of interest have passively safe sign masts been introduced in the USA?  Highway designers here are obliged to consider their use in areas where a collision may occur.

SHA uses wood posts, predominantly, for these kinds of signs. I suspect that if a car hit either wooden post it would (wood?) just punch right through.

DontKnowYet: good point about the 50 sqft thing. This sign is quite large.

[jakeroot]

Out of interest have passively safe sign masts been introduced in the USA?  Highway designers here are obliged to consider their use in areas where a collision may occur.

SHA uses wood posts, predominantly, for these kinds of signs. I suspect that if a car hit either wooden post it would (wood?) just punch right through.

Not familiar with the passive safe sign posts (until I read about it), but it has been quite a while since I've seen a sign go up with wooden posts (in my area of the country, at least).

A bit off-topic, but what exactly is New Zealand using for their sign posts? Here's an example (they're all white).

[roadman]

Wooden posts used to support highway signs can be quite large (usually 6 X 6 or 8 X 8).  Most states that specify wooden posts for either temporary or permanent installations require that the posts have holes cross-drilled through the bottom - at ground level - so they can more easily break away if struck.  Additionally, many states have restrictions on the size of signs that can be mounted on wooden posts (MassDOT, which uses wooden posts only for temporary installations, resticts sign panel size to no more than 50 square feet).

And I'm not sure why people are so concerned about a gore sign that is greater than 50 square feet in area.  For a properly designed and installed steel beam post in concrete foundation support installation, the area of the sign panel shouldn't affect the ability of the breakaway system to prevent the sign panel from entering the vehicle.

[roadfro]

Out of interest have passively safe sign masts been introduced in the USA?  Highway designers here are obliged to consider their use in areas where a collision may occur.

Generally speaking, most state and national guidelines specify that roadside signs be mounted on breakaway sign posts if they are in located within the highway's clear zone. There are a couple varieties and styles, depending on application. Nevada in many applications uses tubular posts that are screwed onto a ground-mounted base, so the pole is designed to break off at the ground level if struck (presumably the whole sign and supports would fall relatively flat to help reduce potential for injuries).

If a sign is too large or support structure needs to be significantly bulky (e.g. Overhead sign support) such that a breakaway post can't be used, then the sign or its support post has to be behind a crash barrier like guard rail or a Jersey wall.

[J N Winkler]

Out of interest have passively safe sign masts been introduced in the USA?  Highway designers here are obliged to consider their use in areas where a collision may occur.

We use drilled wood posts, slip bases (the Texas universal triangular slip base is quite popular, especially in the Western states), hinged posts (quite common on supports for ground-mounted large sign panels--the pictures upthread show at least one example), and guardrail protection for fixed bases.  We do not use Lattix anywhere, to the best of my knowledge.  It is also far less common for US designers to have to consider pedestrian safety adjacent to major roads than in the UK.  The ruling standard is NCHRP 350, which is not the same as that normally used in the UK though DMRB (last I checked) identifies it as an acceptable alternative.