Opinion: Danger ahead: Road signs that are too small or too confusing

[hotdogPi]

Do you really expect a dumbass who can't figure out how to work a credit card terminal to know the difference between a circle 50 shield and a circle 50 speed limit because there's no banner on the speed limit, though?

There's a lot of signs in the MUTCD. The only other circular cutout sign is the railroad crossing sign, and that's yellow with a very clear legend. I don't think people are that stupid.

That said, I prefer Australia's approach anyway, which is the generic speed limit sign covered up with a red circle in the center. If the US ever switches to metric, it would be wise to consider an alternative design like Australia's.

FWIW, I did not know states posted shields without cardinal directions. That's definitely not a thing where I'm from.

I would say circular is not the main point of it. European traffic signage does not rely on words for immediate control functions - and MUTCD spells out everything. I suspect that european signage was developed under assumption that drivers do not have to be literate, and memorizing some pictograms is relatively easy. Sort of pointless by now...

European signage does not rely on words because of the variety of languages in the area.

[webny99]

European signage does not rely on words because of the variety of languages in the area.

There are places in the US, too, where there are many languages spoken. Not to the extent of Europe, but reduced reliance on words can only help in motorist guidance.

[J N Winkler]

Actually, our signing system is designed to accommodate a certain level of mild mental impairment.  Choice of standard letter sizes for signs and limits on message units per sign assembly are based on the assumption that a driver of ordinary mental acuity should be able to read the complete sign message twice in the time it is acceptably visible for reading (defined as a certain range of viewing angles both horizontally and vertically).  The reason for twice-over reading is explicitly to allow the sign to be read at least once by the mentally slow.  This goes all the way back to studies in sign legibility which T.W. Forbes carried out at the (then) Yale Bureau of Street Traffic in the late 1930's.  (I have long suspected, but have not yet proven, that Forbes' research was funded by the Pennsylvania Turnpike Commission for the purpose of developing signs for the original Irwin-Carlisle length.)

I would say circular is not the main point of it. European traffic signage does not rely on words for immediate control functions - and MUTCD spells out everything. I suspect that European signage was developed under assumption that drivers do not have to be literate, and memorizing some pictograms is relatively easy. Sort of pointless by now...

There is a book by Martin Krampen (in German) that deals with the early history of European signing systems.  Belt-and-braces solutions combining symbols and word messages on the same sign panel were actually quite common--Italy and Britain had such systems, for example.  The British experience when transitioning from a mixed to symbol-heavy system in the mid-1960's (pre-Worboys signs to modern Worboys signs) was that sign comprehension immediately went down.

[Scott5114]

Another problem with importing the red circle is that a circular blank is used in Vienna Convention signage for regulatory signage. So putting a speed of 50 on a red circle has legal force behind it.

Under US traffic laws, the equivalent sign is, of course, a white rectangle. So to import this practice and have it have legal meaning, you'd end up with:


Which doesn't really help much.

[kalvado]

Another problem with importing the red circle is that a circular blank is used in Vienna Convention signage for regulatory signage. So putting a speed of 50 on a red circle has legal force behind it.

Under US traffic laws, the equivalent sign is, of course, a white rectangle. So to import this practice and have it have legal meaning, you'd end up with:


Which doesn't really help much.

One of the things that crossed my mind at some point... If US eventually goes to significantly different approach in terms of speed limits and their enforcement  (making them more realistic and serious, not a +10-20MPH speeding on a road underposted by 15 MPH), a new type of speed limit sign would be needed to replace old and heavily compromised type...

[myosh_tino]

One of the things that crossed my mind at some point... If US eventually goes to significantly different approach in terms of speed limits and their enforcement  (making them more realistic and serious, not a +10-20MPH speeding on a road underposted by 15 MPH), a new type of speed limit sign would be needed to replace old and heavily compromised type...

Why would you need a new type of sign?

[kalvado]

Miosh Tino had a good comparison of 3 60x48 road signs:

LEFT: Oregon SPEED sign (60x48, 30-inch Series C digits)
MIDDLE: California SPEED LIMIT sign (60x48, 20-inch Series E or E(M) digits)
RIGHT: FHWA/SHSM SPEED LIMIT sign (60x48, 16-inch Series E digits

And just noticed something that can be placed to the right of this list

[Hurricane Rex]

Got permission from PDX Wanderer to use his picture here: Idaho version of Speed limit 80, notice the series D digits instead of the series C or E used on the previous examples yet everything is still visable from a distance (not seen here). Estimating 24-inch letters.

[myosh_tino]

Idaho version of Speed limit 80, notice the series D digits instead of the series C or E used on the previous examples ... Estimating 24-inch letters.

Interesting.  So I went and found a higher resolution photo of an Idaho 80 MPH speed limit sign and using "pixel math" I came up with this drawing with the following specs...



5.625" -- Top Margin
8.000" -- "SPEED" and "LIMIT" (Series E)
4.125" -- Space between SPEED and LIMIT
5.250" -- Space between LIMIT and Digits
24.00" -- Numerals (Series D)
5.000" -- Bottom Margin

Here are all 4 signs side-by-side-by-side-by-side (OR-ID-CA-FHWA)...

[mrsman]

I think the OR sign should become the national standard.  The numbers are big and easy to see.  We aren't ready in this country to accept a European standard of just a number as it can be easily confused with a highway number, especially in states where the highway symbol is just a rectangle.

[jakeroot]

I think the OR sign should become the national standard.  The numbers are big and easy to see.  We aren't ready in this country to accept a European standard of just a number as it can be easily confused with a highway number, especially in states where the highway symbol is just a rectangle.

I've only seen the Oregon style speed limit sign once in another state. It's a school speed limit sign in Puyallup, Washington (still up as of today). No idea if it's legally enforceable:

[vdeane]

It's also worth noting that even in Oregon, "Speed XX" and "Speed Limit XX" mean two different things.  It is not illegal in and of itself to go faster than a "Speed XX" sign.

[J N Winkler]

I would like to see someone try the "sign didn't use FHWA series" argument before a judge.  It should work, but I know of no previous case where it has been tried.  The "No Stoping" argument did work when it was tried, probably back in the 1930's.

[DaBigE]

I would like to see someone try the "sign didn't use FHWA series" argument before a judge.  It should work, but I know of no previous case where it has been tried.  The "No Stoping" argument did work when it was tried, probably back in the 1930's.

Speaking of "No Stopping"...wonder if someone could get their citation thrown out if they run this red light?

[jakeroot]

I would like to see someone try the "sign didn't use FHWA series" argument before a judge.  It should work, but I know of no previous case where it has been tried.  The "No Stoping" argument did work when it was tried, probably back in the 1930's.

I doubt many people are even aware that all road signs have the same font, never mind that agencies are required to use a specific font.

I would quite like to see the Canadian style "yield at roundabout" sign used, but because it's not an official road sign, there would be no obligation on the part of drivers to observe it as an actual yield sign. Hence why basically everything that's put up on the road has to be to some sort of FHWA standard (and is why I don't believe the sign I posted above is an actual, enforceable speed limit sign).

I would like to see someone try the "sign didn't use FHWA series" argument before a judge.  It should work, but I know of no previous case where it has been tried.  The "No Stoping" argument did work when it was tried, probably back in the 1930's.

Speaking of "No Stopping"...wonder if someone could get their citation thrown out if they run this red light?

I think that goes in the category of "signs that should not be posted where they have been".