Should full matrix DMS be mandated in a future MUTCD?

[Pink Jazz]

In recent years, full matrix DMS have become more popular.  In 2012 ADOT decided to make the switch from fixed character matrix to full matrix.


Today, I decided to email the MUTCD team concerning the issue about the various matrix types for DMS.  I made the suggestion that a future MUTCD should mandate that all new DMS installations should use a full matrix layout to set a floor for legibility.  The problem with fixed character matrix DMS is that all characters are the same width, resulting in wide letters such as "M" and "W" being compressed horizontally, thus reducing legibility.  Line matrix DMS eliminates the character width issue but still restricts character height if the sign is displaying less than the maximum number of lines.


I don't think cost would be much of an issue, since the difference in cost of full matrix displays compared to the other layouts has been shrinking in recent years to the point where some manufacturers are no longer producing fixed character matrix DMS or line matrix DMS.


While the best legibility would be from high resolution, full color DMS, I don't think those should be mandated for now since those are still significantly more expensive than amber-only full matrix displays.  I think having full-matrix amber displays at a minimum should be a good enough floor for legibility.


So, what does anyone here think about the idea of the MUTCD mandating that new DMS installations use full matrix layouts?

[cl94]

Every new VMS I have seen in the past couple years has been full matrix. NYSDOT is in the process of replacing their antiquated fixed character signs, some of which date to the 90s, to very thin full-matrix signs like these. Region 1 has quite a bunch of these, but I've seen them in Region 2 as well. At this point, I don't even know of any fixed character signs that have been installed recently.

[Pink Jazz]

Every new VMS I have seen in the past couple years has been full matrix. NYSDOT is in the process of replacing their antiquated fixed character signs, some of which date to the 90s, to very thin full-matrix signs like these. Region 1 has quite a bunch of these, but I've seen them in Region 2 as well. At this point, I don't even know of any fixed character signs that have been installed recently.

I know about a year ago according to Scott5114 full matrix was still rare in Oklahoma.

Here in Arizona fixed character matrix is still by far the majority, although since 2012 full matrix has been used for new installs; most of Loop 202 is Skyline Products full matrix except for the Red Mountain Freeway west of Gilbert Road (which uses a mix of FDS and Daktronics fixed character matrix signs), with the only remaining portion which has yet to get any DMS installed is on the SanTan Freeway between Ray Road and Broadway (manufacturer is TBD since Skyline's contract expires next July and installation will start in the second half of next year).  New Skyline full matrix signs have also been installed on I-17 in North Phoenix and Anthem, the northernmost part of SR 51, the Loop 101 Agua Fria Freeway (mixed in with a few Daktronics fixed character matrix DMS), I-10 in the West Valley in Avondale and Goodyear, and I-10 in the East Valley in Chandler and the Gila River Indian Reservation.   ADOT has also been installing some smaller Skyline full matrix DMS on some rural state roads as well.

However, at this time ADOT isn't using the full matrix signs to their full potential.

[cl94]

Fixed character is definitely the norm in the northeast and all full-matrix signs tend to have messages that are compatible with fixed character signs. This is outside the US, but I have seen Ontario get pretty creative with their messages. Symbols and everything.

[jakeroot]

I don't know if its necessary to mandate full matrix VMSs. The disadvantages of fixed-character VMSs will slowly make them obsolete regardless of any FHWA ruling.

WSDOT has been installing full-matrix variable message signs for well over a decade now (maybe two).

[Scott5114]

I know about a year ago according to Scott5114 full matrix was still rare in Oklahoma.

They're still quite rare. I did see a portable one along the Turner Turnpike a couple weeks ago, but I know of no permanent full-matrix installs, and even most of the portable ones are still fixed-matrix.

While there are some obvious benefits to a full-matrix VMS, I don't think the legibility concerns are large enough to warrant a mandated phaseout. After all, we are not dealing with halation issues here, and I can't imagine the fixed/variable width difference is going to be great enough to justify the added expense. More likely, a majority of DOTs will simply adopt full-matrix VMSes to take advantage of their benefits, to the point that it will be uneconomical for the vendors to continue producing the fixed-matrix style.

I'm kind of surprised that we haven't developed something more advanced for those big, light-up lane-closure arrow panels yet. I would guess a full-matrix VMS could produce an arrow that looks a lot nicer and might actually aid motorist recognition slightly. At the very least, it might cut down a little on the amount of equipment a contractor needs to keep around.

[jeffandnicole]

Fixed character is definitely the norm in the northeast and all full-matrix signs tend to have messages that are compatible with fixed character signs. This is outside the US, but I have seen Ontario get pretty creative with their messages. Symbols and everything.

Why do you keep referring to the 'Northeast' as a region in whole?  Pennsy & NJ have been using full matrix signage for years now.  Both the NJ and PA Turnpikes have full-color DMS signage, and even NJDOT appears to be purchasing full matrix, full color DMS units lately.

You're better off specifying the states you are referring to, because you're incorrect when referring to the entire Northeast.

[jakeroot]

Fixed character is definitely the norm in the northeast and all full-matrix signs tend to have messages that are compatible with fixed character signs. This is outside the US, but I have seen Ontario get pretty creative with their messages. Symbols and everything.

Why do you keep referring to the 'Northeast' as a region in whole?  Pennsy & NJ have been using full matrix signage for years now.  Both the NJ and PA Turnpikes have full-color DMS signage, and even NJDOT appears to be purchasing full matrix, full color DMS units lately.

You're better off specifying the states you are referring to, because you're incorrect when referring to the entire Northeast.

He never said that full-matrix VMSs didn't exist in the northeast. He just said they weren't "the norm". And if they only exist on two roads, that's accurate.

[UCFKnights]

I know about a year ago according to Scott5114 full matrix was still rare in Oklahoma.

They're still quite rare. I did see a portable one along the Turner Turnpike a couple weeks ago, but I know of no permanent full-matrix installs, and even most of the portable ones are still fixed-matrix.

While there are some obvious benefits to a full-matrix VMS, I don't think the legibility concerns are large enough to warrant a mandated phaseout. After all, we are not dealing with halation issues here, and I can't imagine the fixed/variable width difference is going to be great enough to justify the added expense. More likely, a majority of DOTs will simply adopt full-matrix VMSes to take advantage of their benefits, to the point that it will be uneconomical for the vendors to continue producing the fixed-matrix style.

I'm kind of surprised that we haven't developed something more advanced for those big, light-up lane-closure arrow panels yet. I would guess a full-matrix VMS could produce an arrow that looks a lot nicer and might actually aid motorist recognition slightly. At the very least, it might cut down a little on the amount of equipment a contractor needs to keep around.

In Orlando I have seen them on occasion use full matrix VMSes as arrow panels for a couple years now. Still rare, perhaps they only use it if the regular ones aren't available.

[jemacedo9]

Fixed character is definitely the norm in the northeast and all full-matrix signs tend to have messages that are compatible with fixed character signs. This is outside the US, but I have seen Ontario get pretty creative with their messages. Symbols and everything.

Why do you keep referring to the 'Northeast' as a region in whole?  Pennsy & NJ have been using full matrix signage for years now.  Both the NJ and PA Turnpikes have full-color DMS signage, and even NJDOT appears to be purchasing full matrix, full color DMS units lately.

You're better off specifying the states you are referring to, because you're incorrect when referring to the entire Northeast.

He never said that full-matrix VMSs didn't exist in the northeast. He just said they weren't "the norm". And if they only exist on two roads, that's accurate.

PennDOT has been installing them in the Phila area over the past couple of years, mainly replacing older ones. I-76, I-476, I-95, and US 202 have them in a couple of places, and I believe more are being installed currently.

[cl94]

Pennsylvania and New Jersey are 2 states out of nearly a dozen. I'm well aware of how they apply VMSes. I also know that the New England states tend to use fixed character.

[roadman]

MassDOT has been steadily transitioning to the use of full matrix CMS panels for both permanent installations and portable signs for the past few years.  The pending project (Project # 606927) to replace the last of the mid-1990s and Big Dig era CMS panels within the Greater Boston area calls for the new panels to be full matrix as well.

[Pink Jazz]

I know about a year ago according to Scott5114 full matrix was still rare in Oklahoma.

They're still quite rare. I did see a portable one along the Turner Turnpike a couple weeks ago, but I know of no permanent full-matrix installs, and even most of the portable ones are still fixed-matrix.

While there are some obvious benefits to a full-matrix VMS, I don't think the legibility concerns are large enough to warrant a mandated phaseout. After all, we are not dealing with halation issues here, and I can't imagine the fixed/variable width difference is going to be great enough to justify the added expense. More likely, a majority of DOTs will simply adopt full-matrix VMSes to take advantage of their benefits, to the point that it will be uneconomical for the vendors to continue producing the fixed-matrix style.

I'm kind of surprised that we haven't developed something more advanced for those big, light-up lane-closure arrow panels yet. I would guess a full-matrix VMS could produce an arrow that looks a lot nicer and might actually aid motorist recognition slightly. At the very least, it might cut down a little on the amount of equipment a contractor needs to keep around.

Some manufacturers apparently don't produce fixed character matrix or line matrix DMS anymore. The product specifications on the Daktronics and Skyline websites only show the specs for full matrix signs.  This makes me think that the cost difference is already shrinking. I think Daktronics may have stopped producing fixed character matrix signs after the ADOT contract expired in 2012. Not sure who was the most recent DOT to purchase line matrix signs from Daktronics, however.

[roadman]

Not sure who was the most recent DOT to purchase line matrix signs from Daktronics, however.

Not a highway application, but the train information boards at North and South Stations in Boston are Daktronics line matrix signs.  They were installed in 2007.

[cl94]

Not sure who was the most recent DOT to purchase line matrix signs from Daktronics, however.

Not a highway application, but the train information boards at North and South Stations in Boston are Daktronics line matrix signs.  They were installed in 2007.

Daktronics still sells those, but they're going to full matrix for most of them (i.e. the new-ish signs on the IRT in New York).

[Pink Jazz]

Not sure who was the most recent DOT to purchase line matrix signs from Daktronics, however.

Not a highway application, but the train information boards at North and South Stations in Boston are Daktronics line matrix signs.  They were installed in 2007.

ADOT signed its contract with Daktronics that same year for its fixed character matrix signs, which lasted until 2012.  One additional sign was installed in 2014 in the Tucson area; this sign was manufactured during the time Daktronics held the contract, but got stranded with Daktronics after its contract expired due to project delays, thus ADOT issued a separate purchase order to pay for and obtain this sign.

Interestingly, in addition to ADOT being late to the full matrix party, they were also late to the LED party since the Daktronics signs were the first LED signs to be purchased by ADOT.  From 1997 to 2007 (renewed once in 2002 I think), ADOT's contract was with Fiber Display Systems for fiber optic fixed character matrix SYLVIA signs.  Many of the FDS SYLVIA signs have since been refurbished with SES America's LED retrofit package.

[roadman]

ADOT's contract was with Fiber Display Systems for fiber optic fixed character matrix SYLVIA signs.  Many of the FDS SYLVIA signs have since been refurbished with SES America's LED retrofit package.

A number of the signs to be replaced under the pending MassDOT retrofit contract are either FDS SYLVIA or MARK IV fiber optic fixed matrix signs.  As MassDOT no longer specifies walk-in cabinets for overhead CMS signs, the existing signs will be completely replaced with new front-access panels (mostly retaining the existing support trusses) instead of being retrofitted.

[Pink Jazz]

ADOT's contract was with Fiber Display Systems for fiber optic fixed character matrix SYLVIA signs.  Many of the FDS SYLVIA signs have since been refurbished with SES America's LED retrofit package.

A number of the signs to be replaced under the pending MassDOT retrofit contract are either FDS SYLVIA or MARK IV fiber optic fixed matrix signs.  As MassDOT no longer specifies walk-in cabinets for overhead CMS signs, the existing signs will be completely replaced with new front-access panels (mostly retaining the existing support trusses) instead of being retrofitted.

Speaking of walk-in cabinets, ADOT's latest RFP for its largest full matrix signs include provisions for both walk-in and front access cabinets, unlike the current contract with Skyline which specifies walk-in for its largest size (primarily for freeway installs) and front access for smaller sizes (primarily for rural non-freeway roads). Perhaps the large front access signs may be used for roadside ground-mounted installs.