Color Of Variable Speed Limit Signs Could Jeopardize Criminal Cases Resulting From Speeding Offense Probable Cause

By Darren Smith, Weekend Contributor

variable-speed-yellow-black-largeCriminal Cases resulting from speeding offense probable cause may be in jeopardy due to improper colors used variable speed limit signs. If courts determine that these signs violate statutory signage standards, exclusionary rules may apply resulting in dismissals of numerous criminal cases.

An example of this is found on Interstate 90 straddling Snoqualmie Pass in Washington State. Over a decade ago, the Washington State Department of Transportation installed Highway Advisory Beacons, near the mountain pass to warn driver of upcoming hazards along with incorporation into the state’s variable speed limit statute. An example of these types of signs is pictured above.

At issue is the coloring used.


These signs are colored orange/yellow upon a black background. Standardized speed limit signs are colored either black on a white background or white on a black background. These colors among others are Regulatory in nature. Yellow or orange are cautionary or advisory. The lack of proper color means that these signs are not regulatory in nature and are not true speed limit signs so they could be held to be unenforceable as speed limit signs.

Modifying speed limit, in this case the variable speed limit, means that the statutory speed limit of sections of highway having these signs would be a different rate or the designated speed limit between the last and the next regular speed limit signs at the respective ends of the variable speed zone.

If the variable speed limit is held to be invalid and the probable cause for the stop was for exceeding the limit defined in the variable speed limit (if below the default speed limit) a suppression hearing may result in criminal cases being dismissed.

Anecdotally, if such a traffic stop occurred, evidence of DUI, possession of controlled substances, license violations, and other felonies these might not make it to trial because the signage of the variable speed limit is incorrectly formatted and colored; and is not a true speed limit sign.

Here is an analysis of the issue:

While other states could have differing traffic laws underlying this, they all adopt the federal standard governing traffic control devices by reference or mandate.

From the United States Department of Transportation | Federal Highway Administration

mutcdThe Manual on Uniform Traffic Control Devices, or MUTCD defines the standards used by road managers nationwide to install and maintain traffic control devices on all public streets, highways, bikeways, and private roads open to public travel. The MUTCD is published by the Federal Highway Administration (FHWA) under 23 Code of Federal Regulations (CFR), Part 655, Subpart F.
The MUTCD, which has been administered by the FHWA since 1971, is a compilation of national standards for all traffic control devices, including road markings, highway signs, and traffic signals. It is updated periodically to accommodate the nation’s changing transportation needs and address new safety technologies, traffic control tools and traffic management techniques.

The Manual on Uniform Traffic Control Devices, or MUTCD defines the standards used by road managers nationwide to install and maintain traffic control devices on all public streets, highways, bikeways, and private roads open to public travel. The MUTCD is published by the Federal Highway Administration (FHWA) under 23 Code of Federal Regulations (CFR), Part 655, Subpart F.

The MUTCD, which has been administered by the FHWA since 1971, is a compilation of national standards for all traffic control devices, including road markings, highway signs, and traffic signals. It is updated periodically to accommodate the nation’s changing transportation needs and address new safety technologies, traffic control tools and traffic management techniques.

On December 16, 2009 a final rule adopting the 2009 Edition of the MUTCD was published in the Federal Register with an effective date of January 15, 2010. States must adopt the 2009 National MUTCD as their legal State standard for traffic control devices within two years from the effective date.

The MUTCD has traffic control device standards establishing a myriad of signage and traffic devices. The following paragraphs are pertinent to this discussion.

Section 2B.02 Design of Regulatory Signs


01 Regulatory signs shall be rectangular unless specifically designated otherwise. Regulatory signs shall be designed in accordance with the sizes, shapes, colors…

Section 1A.12 Color Code

01 The following color code establishes general meanings for 11 colors of a total of 13 colors that have been identified as being appropriate for use in conveying traffic control information. tolerance limits for each color are contained in 23 CFR Part 655, Appendix to Subpart F and are available at the Federal Highway Administration’s MUTCD website at or by writing to the FHWA, Office of Safety Research and Development (HRD-T-301), 6300 Georgetown Pike, McLean, VA 22101.

02 The two colors for which general meanings have not yet been assigned are being reserved for future applications that will be determined only by FHWA after consultation with the States, the engineering community, and the general public. The meanings described in this Section are of a general nature. More specific assignments of colors are given in the individual Parts of this Manual relating to each class of devices.


03 The general meaning of the 13 colors shall be as follows:

A. Black—regulation
B. Blue—road user services guidance, tourist information, and evacuation route
C. Brown—recreational and cultural interest area guidance
D. Coral—unassigned
E. Fluorescent Pink—incident management
F. Fluorescent Yellow-Green—pedestrian warning, bicycle warning, playground warning, school bus and school warning
G. Green—indicated movements permitted, direction guidance
H. Light Blue—unassigned
I. Orange—temporary traffic control
J. Purple—lanes restricted to use only by vehicles with registered electronic toll collection (ETC)
K. Red—stop or prohibition
L. White—regulation
M. Yellow—warning


Here is where the problem begins with the subject variable speed limit signs. According to the color legend, black and white are regulatory. Black and White signs are regulatory. Yellow signs for example are warning and orange are temporary traffic control.

An argument can be made that the subject road signs have a black background and therefore are regulatory. However this might not be the case due to the structure of the sign. It might be considered a hybrid beacon regarding the black background.

Section 1A.13 Definitions of Headings, Words, and Phrases in this Manual

88. Hybrid Beacon—a special type of beacon that is intentionally placed in a dark mode (no indications displayed) between periods of operation and, when operated, displays both steady and flashing traffic control signal indications.

A beacon is defined as a device having the capability of displaying a sign or traffic signal. In this respect it can be asserted that the Variable Speed Limit display device is a form of Hybrid Beacon. As such it would preempt the notion of a black background being a sign of a regulatory speed sign.

But for reference this can be disputed under the reflectivity and illumination standards of the MUTCD which refers to LED lighting.

Section 2A.07 Retroreflectivity and Illumination


02 Regulatory, warning, and guide signs and object markers shall be retroreflective (see Section 2A.08) or illuminated to show the same shape and similar color by both day and night, unless otherwise provided in the text discussion in this Manual for a particular sign or group of signs.

03 The requirements for sign illumination shall not be considered to be satisfied by street or highway lighting.

07 Except as provided in Paragraphs 11 and 12, neither individual LEDs nor groups of LEDs shall be placed within the background area of a sign.

08 If used, the LEDs shall have a maximum diameter of 1/4 inch and shall be the following colors based on the type of sign:

A. White or red, if used with STOP or YIELD signs.
B. White, if used with regulatory signs other than STOP or YIELD signs.
C. White or yellow, if used with warning signs.
D. White, if used with guide signs.
E. White, yellow, or orange, if used with temporary traffic control signs.
F. White or yellow, if used with school area signs.

Compliant Variable Speed Signage
Compliant Variable Speed Signage

Under 08/B “regulatory signs other than STOP or Yield signs” would include Speed Regulations. In this case white must be used. This LED standard could be imported into the type of road sign for this article.


In the traffic legend, black lettering on a yellow background denoting speed is an advisory sign. Advisory speed signs are recommendations to the driver of suggested speed limits based upon terrain or other conditions. Advisory signs, since being non-regulatory, do not carry enforceable elements to allow for a violation of a speed regulation at a presumptive level.

As such of the yellow / orange illuminated sign used a variable speed zone setting could be unenforceable as a regulatory speed sign.

There could be an argument as to the initial signs that precede these speed signs are regulatory in that they are black on white and read “Variable Speed Limit Ahead” and are followed by signage indicating the actual statutory speed limit. However, since the signage showing a lowered speed limit does not comply to the color standard for a regulatory speed limit sign, it is on the same non-enforceable standard as an advisory sign that is permanently installed at locations such as a curve in the roadway.

If the interpretation of the color scheme used in the subject variable speed limit sign is a temporary traffic control zone, it does not permit that the sign color legend for speed limit signs be changed from their standardized regulatory colors. Moreover, temporary traffic control signage is designed to not be permanent in nature—which is the case with these large signs permanently installed adjacent to the freeway.

Using Washington law as a template, the state adopts by reference a standard manual for traffic control. RCW 47.36.030 reads under section (1):

The secretary of transportation shall have the power and it shall be its duty to adopt and designate a uniform state standard for the manufacture, display, erection, and location of all signs, signals, signboards, guideposts, and other traffic devices erected or to be erected upon the state highways of the state of Washington for the purpose of furnishing information to persons traveling upon such state highways regarding traffic regulations, directions, distances, points of danger, and conditions requiring caution, and for the purpose of imposing restrictions upon persons operating vehicles thereon. Such signs shall conform as nearly as practicable to the manual of specifications for the manufacture, display, and erection of uniform traffic control devices for streets and highways and all amendments, corrections, and additions thereto.

The Washington State Department of Transportation (WSDOT) adopted the MUTCD 2009 on November 17, 2011. The MUTCD 2009 and Washington Modification are effective for use in Washington beginning December 19, 2011. In doing so the state is bound to the parameters of the MUTCD in enforcing the signage standards that could be in conflict with some of its variable speed zones.

your-speedThe Washington Modification is contained in Chapter 468-95 of the Washington Administrative Code. In that under 468-95-045 mentions the issue of colors relating to changeable message signs indicating approaching vehicle’s speed as being yellow and black, it is a guideline and not a standard as is indicated for speed limit signage.

The subject variable speed limit signs on Interstate 90 and other locations are of an older technology than what is presently installed elsewhere. These newer models have the ability to display numerous or at least compliant color schemes. If WASDOT failed to specify a correct color and for that there could be significant legal repercussions resulting. This might also require a retrofitting of these non-compliant electronic signs and such measures could involve significant costs to the state.

Until this is corrected, county prosecutors, law enforcement agents, and defense attorneys might want to consider reviewing the matter.

By Darren Smith


Manual on Uniform Traffic Control Devices (MUTCD)
Washington State Department of Transportation
Chapter 47.36 Revised Code of Washington
Chapter 468-95 Washington Administrative Code

The views expressed in this posting are the author’s alone and not those of the blog, the host, or other weekend bloggers. As an open forum, weekend bloggers post independently without pre-approval or review. Content and any displays or art are solely their decision and responsibility.

19 thoughts on “Color Of Variable Speed Limit Signs Could Jeopardize Criminal Cases Resulting From Speeding Offense Probable Cause”

  1. Tyger, unless you’re in Albuquerque. There, green means go, yellow is green, red is just a suggestion (at least for the next three cars).

  2. Teacher: “Johnny, what do the three colors of a traffic light mean?”
    Johnny: “Red means stop. Green means go. Yellow means go faster.”

  3. Question: Why is a stop light red? Answer: You would be red, too, if you had to stop and go in the middle of an intersection.

  4. Isn’t this kind of a King v. Burwell issue??? If the courts decide on the literal black letter meaning of the statutes, then there will be a lot of disruption and financial loss to the entities issuing the tickets. OTOH, if the court takes a broad view of what the signs were supposed to mean, then everything goes on as before.

    Squeeky Fromm
    Girl Reporter

  5. Karen, Great story about your dad and the Korean man and daughter. You and DBQ are gems here. Absolute gems.

  6. DBQ – that’s true. My dad is color red green color blind. That’s why it was so important to standardize the placement of the lights on signals for people like him.

  7. Great article, Darren. It sounds like all of those traffic stops were indeed invalid.

    Nick – I really need to get my own eyes fixed, as well, due to near sightedness. Without my contacts in, I’d walk into walls. But I’m chicken. It’s just the thought of surgery on my eyes while I’m awake that freaks me out.

    My father had cataract surgery a couple of years ago. They found a great doctor, and they made arrangements for my mother to stay next to him during the procedure. That gave him confidence that he had an advocate while he was helpless, if he needed one. He was completely relaxed and had an easy experience. While he was in recovery, a Korean gentleman came in for the same surgery. Every time they tried to start, his blood pressure sky rocketed, and they had to stop. The doctor looked a long moment at my dad, laughing and joking in recovery, and asked the family of the Korean man, who spoke zero English, if one of them would sit with him. His daughter did, who spoke perfect English, and the man’s blood pressure evened out and he calmly had the surgery. Just having someone you trust with you, and in this case, able to translate if you feel pain, can make all the difference in the experience.

  8. Montana made it quite easy for a period of time in the late 90s with no posted daytime speed limits on interstate highways. No sign, no problem.

    1. ModernMiner – Montana did the same thing in the early 60s. The only people being killed were tourists so there was no reason to change it. However, if you went 56 at night you got a ticket.

  9. Another interesting weekend post. I have an increasingly difficult time driving @ night. If it’s raining as well, Fuggedaboutit. Being diabetic, I do my due diligence and have yearly eye exams. My vision is quite good. I only need level 2 glasses to read. But, I have cataracts. The clouding caused by cataracts is what makes night vision so difficult. Most folks don’t get yearly exams so they would not know they have cataracts. The surgery is easy and fairly economic as surgeries go. My doc said when you think it’s hazardous, then come in and I’ll do the surgery. I think this is the year.

    Again, the meanies don’t usually comment on these threads. So, hello to all the nice folk. There are some real sewer threads ongoing. These are respites.

  10. Chinggis now know that if Chinggis pulled over for speeding in USA, Chinggis ask officer: ” What’s your sign?” Chinggis also need to learn sign language.

  11. Oh Man! My mother and brother would be in BIG trouble with all these colored signs and confusion…….they are COLOR BLIND. Green and yellow look the same. Blue and brown are the same. God only knows what florescent pink or green look like to them.

    What confustion.

  12. Thanks for an interesting article, Darren. I’ve driven over Snoqualmie Pass a lot over the years.
    Re the possible exclusion of evidence found in the course of a disputed traffic stop, of drug possession, etc., I think that Heien v. North Carolina make a motion to suppress unlikely to succeed.
    The Court essentially ruled that even if an officer pulled over a vehicle in the mistaken belief that a tail light malfunction was illegal (N. Carolina only requires one working brake light, and the stop was made because the other bulb malfunctioned), evidence found “incidental” to the erroneous stop was still admissible.

  13. I have not been charged with a ticket in many, many, many years. Still, I will have to check out Arizona to see if you are in the same fix.

  14. All I know is, that the casino tour buses going to Atlantic city, NJ or the Mohegan Sun in CT, are always in the left lane speeding. You might say it’s a gamble. Place your bets.

  15. Jeez Darren when did everything get so complicated???? 😉 great article well researched

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