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Note: This is a Brief, not Case Law and is presented to help the Trier of Facts understand the CFR regulations and how they apply to the speed limit and the enforceability of speed limits that have been set if they are not in compliance of the mandatory road speed survey.





Citation ID. NO. 28875


DEFENDANT FLOYD L. PHILLIPS, in pro per, hereby moves to dismiss the complaint with prejudice, and in support of his declaration states:
The case arose on the 4th day of December 2000; the Defendant PHILLIPS was stopped and cited by a Cass County deputy sheriff for exceeding an alleged lawfully POSTED 55 MPH SPEED LIMIT on Dailey Road in Cass County; a violation of MI 257.627–8.
This case is matter of law. The State’s prosecution is based on “MI 257.627 Speed limitations” and its supporting authorities in 257.628 and 257.629 et al., and elsewhere that purports to authorize an invented 55 mile per hour numeric to be displayed on official federal regulatory traffic control devices – a violation of Title 23 of the US Code of Federal Regulations. Therefore, the state relied on its own wrongdoing as the starting place of the process.


1. ON ITS FACE MI 257.627 Speed limitations, and its supporting authorities 257.628 and 257.629 et al. is in conflict with controlling federal law.
Mandatory conformity with National Traffic Control Standards has been required on all federally funded highways since 1944. In 1966, Congress passed the HIGHWAY SAFETY ACT, where they expanded ITS MANDATES TO INCLUDE ALL ROADWAYS OPEN TO THE PUBLIC. To empower this Act, CONGRESS resolutely PREEMPTED ALL STATE TRAFFIC CONTROL LAWS to facilitate the adoption of a uniform NATIONAL TRAFFIC CONTROL STANDARD. Under Title 23, this act mandated conformity with The National Manual of Uniform Traffic Control Devices (MUTCD) and its referenced nationally recognized professional engineering standards and practices – therefore, they too are federal law.
Traffic control devices are all signs, signals, markings, and devices placed on, over, or adjacent to a street or highway by authority of a public body or official having jurisdiction to regulate, warn, or guide traffic.

The need for high uniform standards was recognized long ago. The American Association of State Highway and Transportation Officials published a manual for rural highways in 1927 and the National Conference on Street and Highway Safety published a manual for urban streets in 1929. But the necessity for unification of the standards applicable to the different classes of road and street systems was obvious. To meet this need, a joint committee of the American Association of State Highway and Transportation Officials and the National Conference on Street and Highway Safety developed, and published in 1935, and original edition of this Manual of Uniform Traffic Control Devices. That committee, though changed from time to time in organization and personnel, has been in continuous existence and has contributed to periodic revisions of the Manual, including this 1988 edition. The committee’s name was formally changed to the National Committee (NC) on Uniform Traffic Control Devices.”

"2b–10 Speed Limit Sign, (R2-1)
The Speed Limit sign shall display the limit established by law, or by regulation, after an engineering and traffic investigation has been made in accordance with established traffic engineering practices. The speed limits shown shall be in multiples of 5 miles per hour.
There is no authority granted in Title 23 for a state to post an INVENTED NUMERIC on an official traffic control device (MUTCD 2B–10, Speed Limit Sign, R2–1). Federal regulations require that any speed limit, whether the limit is established by legislative or administrative action, be determined on the basis of an engineering investigation (study) as specified in MUTCD 2B–10. The Supremacy clause provision under Article IV, Section 2 of the U.S. Constitution, providing that federal law is superior to and overrides state law when they conflict; therefore, the posted limits are unlawfully posted.
2. INVENTED NUMERIC in this context of science represents in law the phrase “arbitrary and capricious”.
The NUMERIC posted on an official traffic device R2–1 Speed Limit sign, under federal law is an engineering determined regulatory value that speeds in excess of represents an unacceptable hazard to others. A well established matter of science, where the safe for conditions value is determined by site specific Basis–in–Fact finding, “after an engineering and traffic investigation has been made in accordance with established traffic engineering practices”. Without such a finding–of–fact for the particular section of highway taking into account all the conditions present, the exercise of police powers enforcing a regulatory speed limit with an invented numeric value has no factual foundation.
ARBITRARY: 1, depending on individual discretion (as of a judge) and not fixed by standards, rules, or law; not restrained or limited in the exercise of power; marked by or resulting from the unrestrained exercise of power. 2 a, based on preference, bias, prejudice, or convenience rather than on reason or fact, an arbitrary standard; b, existing or coming about seemingly at random or by chance or as an unreasonable act of individual will without regard for facts or applicable law.
CAPRICIOUS: 1, governed or characterized by impulse or whim: as; lacking a rational basis; likely to change suddenly. 2, not supported by the weight of evidence or established rules of law.
The 55 MPH numeric incorporated into the statute contrary to law, and is an “arbitrary and capricious” established number as is the prosecution of the defendant for violating such a number.
3. Attached exhibit #1 & #2, correspondence from the Cass County Public Works Department that clearly affirms that the speed limit on this particular section of highway was posted in accord with the legislated MI 257.627 Speed limitations, and its supporting authorities 257.628 and 257.629 et al., a STATUTORY 55 MPH MANDATE WITHOUT THE REQUIRED ENGINEERING STUDY. Excerpts;
"Dear Mr. Phillips:
There has not been an engineering study conducted on Dailey Road between Pokagon Highway and Beeson Street in the last five (5) years. That section of Dailey Road was changed from a local road to a primary road in 2000."

"The speed limit on all county roads is set by state statute. It is 55 miles per hour, or the reasonable safe speed under the existing conditions, unless it is set at a speed lower than 55 miles per hour and a speed sign is posted."
Therefore the posted speed limit on its face, as a matter of law, was posted unlawfully under controlling federal law.
4. The county has not produced a study, or have they cited a Title 23 Code of Federal Regulation authority, which authorizes them to post a MUTCD 2B–10, Speed Limit Sign, R2–1, without its conditions precedent being met. Nothing has been presented to controvert the defendant’s case law and federal statute cites, that clearly show the limit was unlawfully posted.
5. The county’s prosecution was initiated under the color of federal law, which includes all regulatory traffic control on any roadway open to the public. To wit, the citation was issued for violating the speed limit in a posted speed zone, the violation of a posted regulated traffic control device (federal designation R2–1, Speed limit sign), the control remedy Congress chose to accomplish conformance with its stated safety objectives and uniform national standard.
Consequently, all regulatory traffic control is clearly under federal dominion and its required conditions precedent. Therefore, the county, absent the required conditions precedent, can not make any assertion that a lawfully posted speed limit was violated, their argument becomes moot and the Court must grant this "Motion to Dismiss".
6. Every time Michigan accepts Federal highway funds on any project, the state certifies under the conditions precedents in 23 CFR 630.307 that the above federal regulations have been, and are currently being complied with; and the state’s use of these Federal Official Traffic Control Devices (Speed Limit Sign, R2–1) have met the conditions precedents that the state must comply with prior to their use on a public highway.
CFR 630.307 Agreement provisions.
The State, through its highway agency, accepts and agrees to comply with the applicable terms and conditions set forth in title 23, United States Code, Highways, the regulations issued pursuant thereto, the policies and procedures promulgated by the FHWA relative to the designated project in which the FHWA authorized certain work to proceed, and all other applicable Federal laws and regulations.
Title 23 encourages, but it doesn’t require, states to adopt the MUTCD mandated compliance language into their state statutes; notwithstanding, if the state accepts federal highway funds, compliance with all provisions of Title 23 and its designated MUTCD is mandatory on all roads open to the public within that state.
Moreover, the state can not grant itself authority to use any device without the federal conditions precedent being met; to wit, the posting of an invented numeric on a R2-1 Speed Limit Sign without an engineering study using nationally accepted engineering procedures and practices that support the number posted.
The state’s certified compliance with the Title 23 highway fund provisions binds the state to the supremacy of the relative sections of the Code of Federal Regulations. The regulatory traffic control devices the defendant allegedly violated where not lawfully established as required in the Title 23.
In a like manner, Title 23 also requires states to conduct periodic traffic engineering studies with corresponding safety reviews on all roadways (POSTED OR UNPOSTED) within in its requirements for states to have highway safety programs independent of federal aid on any particular highway. This program includes the funds to assist the states in bringing traffic control devices into conformity. And that within 2 years of any rule change, all traffic control shall be brought into compliance.
Michigan certifies under two separate administrative funding sections of Title 23 that they have conducted the required traffic engineering studies that could be the basis for establishing speed limits where warranted. Therefore, no claim can be made by the state that this requirement of compliance would cause an undo burden or an unfunded mandate. This posted speed zone was established contrary to the state’s compliance certification, therefore the state is prosecuting the defendant for violating an unlawfully posted numeric limit.
7. The Legislature in MI 257.627 Speed limitations, and its supporting authorities 257.628 and 257.629 et al., placed itself superior to federal law on select Michigan roadways, while requiring any deviation from their mandates to be in full compliance with same US Code Title 23 mandates.
Title 23 is the standard to be followed, not the exception – there are no lawful exceptions. The STANDARD: MUTCD 2B–10, Speed Limit Sign, R2–1, “according to an engineering study” for that particular section of roadway, that supports the numeric posted. Therefore, ON ITS FACE MI 257.627 Speed limitations, and its supporting authorities 257.628 and 257.629 et al. is void because it is in conflict with federal law. This law couldn’t be clearer, “there are no exceptions” with compliance.
“FHWA website, MUTCD – Frequently Asked Questions–faq.htm
What is the Manual on Uniform Traffic Control Devices (MUTCD)?

The Federal Highway Administration (FHWA) publishes the MUTCD, which contains all national design, application, and placement standards for traffic control devices. The purpose of these devices, which includes signs, signals, and pavement markings, is to promote highway safety, efficiency, and uniformity so that traffic can move efficiently on the Nation's streets and highways.

What is the legal status of the MUTCD?

The MUTCD is adopted by reference in accordance with title 23, United States Code, Section 109(d) and Title 23, Code of Federal Regulations, Part 655.603, and is approved as the national standard for designing, applying, and planning traffic control devices.

Does this mean that all traffic control devices must comply with MUTCD standards?

Yes, all traffic control devices nationwide must conform to the MUTCD. There are no exceptions.”
8. Title 23 is a UNIFORM NATIONAL STANDARD FOR TRAFFIC CONTROL. This means a uniform national design, placement and application on all roadways in the Nation. In accord with Interstate Commerce and Title 23 provisions, uniformity within a state is not uniformity. Uniformity in application can only be achieved when like conditions in all states are treated equally, where the procedures and practices applied are the same – in compliance with the conditions precedent in the National MUTCD.
No arbitrary Michigan specific legislated statutory speed limit can be in congruity with posted limits on like highways in Wisconsin, Montana, Nevada, Maine, Florida, Texas etc.. Further, Title 23 requires location specific determinations because even within Michigan, all highways under a fixed statutory invented numeric do not have the same service levels, design, development, terrain and prevailing speeds; therefore, invented statutory limits are by definition “arbitrary and capricious” law. Moreover, highways and freedom of travel come under interstate commerce, divergent local application of police powers enforcing non-complying devices or non–standard application under the authority of a national standard rises to a violation of the motorist’s equal protection rights.
Example of such an errant provision in a statute.

MCL 257.628(1), which states, “The maximum speed limit on all highways or parts of highways upon which a maximum speed limit is not otherwise fixed pursuant to this act shall be 55 miles per hour.”
All speed limits must be determined on location specific findings on a case by case basis in accordance with the conditions precedent in Title 23. Therefore as a matter of law on its face, this MICHIGAN statute’s invented 55 numeric is in violation of federal law.
9. The NUMERIC is Non–fact–based, HENCE UNCONSTITUTIONAL. The United States Constitution requires that laws be fact–based. A non–fact–based law violates due process. Why? Due process includes the notion that, on science and engineering issues and such type issues, only facts will be presented in court, not myth, not speculation. Case law to the same effect where the EPA established an unsupported by science regulation, Industrial Union Dept. v. American Petrol. Inst., 448 U.S. 607 (1980)
The 55 MPH per hour invented numeric in MI 257.627 Speed limitations, and its supporting authorities 257.628 and 257.629 et al. violates due process on–its–face on two counts. First because there is no authority within the federal law and its MUTCD to post arbitrary numeric on an official regulated traffic control device nor is there authority to post any device except those that are in full compliance with said law. Second because it is an invented numeric; using invented numbers to represent numeric values that are resolutely identified as matters of science is unconstitutional and violates due process.
Contrary to the requirements of the aforesaid federal laws, engineering findings and the due process clause of the Constitution, the numeric is an invented number. It was inserted into the said state statutes by a political body, without supporting location specific fact–based engineering studies determining the appropriate numeric value for that particular section of highway... and the invented numeric is in direct conflict to the body of knowledge that is the core of the traffic safety engineering profession’s findings – a matter of science; as required by the aforesaid federal law and due process provisions. Therefore, the invented statutory 55 MPH numeric violates due process.
10. MI 257.627 Speed limitations, and its supporting authorities 257.628 and 257.629 et al. prescribed arbitrary statutory numeric violates a defendant’s due process to confront the source, and validity of the evidence that is the basis of the state’s prosecution. There is no method to challenge the validity of an invented numeric. This is a standard without a standard to be met. Thereby denying due process remedies;
People v. Ellis, (1995) 33 Cal. App, 4th 525 “Since the summary contained none of the raw data collected during the survey, how could the defendant have shown that the survey was inadequate?” “Allowing a defendant to attack the adequacy of an engineering and traffic survey if the document is not available for his or her use at trial.”
Superior Court of the State of California, for the County of Ventura, Appellate Department, case no.: 13 Cal, App.4th Supp. I 1992 the People vs. Goulet. Conclusion; “The survey in this case did not justify the prima facie speed limit.”
11. Absent compliance with the MUTCD CONDITIONS PRECEDENT, the purported numeric is void. The defendant is an experienced driver and undoubtedly the court is. So we are all well and jointly aware that there is a significant federal control of interstate highways pursuant to the national defense concept promoted by said freeways pursuant to the constitutional authority to defend the nation.
Congress can itself set speed limits, and we know, has done so at two points in our nation’s history. That last action was called the National Maximum Speed Limit (NMSL) in response to National Fuel Emergency.
When the NMSL was repealed in 1995, that of course did NOT repeal all the prior existing and still extant law, including the aforesaid requirements that traffic control devices be fact–based and in compliance with the National MUTCD. The 55 MPH numeric is posted absent the conditions precedent required in prior existing and extant law; therefore, the posted numeric is void.
12. Under “the color of federal law” the state is enforcing a state traffic control law that is not in compliance with its governing National standard, a violation of due process and the equal protection clause. CUSTOMS AND USAGES DO NOT DEFINE OR CREATE LAW. In law, "what ought to be done us fixed by a standard . . . whether it usually is complied with or not." Texas & Pac Ry v Behymer, 189 US 468, 470; 23 S Ct 622, 623; 47 L Ed 903 (1903). Law exists, is "designed to disrupt," nonconforming practice, U.S. v City of Los Angeles, 595 F2d 1386, 1391 (CA 9, 1979). A "practice" "not based upon any rule of law" must be reversed, Biafore v Baker, 119 Mich App 667; 326 NW2d 598 (1982); The T. J. Hooper, 60 F2d 737, 740 (CA 2, 1932). But sometimes, violations in disregard of the rule of law, have developed, and continued through generations. Nonetheless, the Constitution is "designed to disrupt" practice, so customs and usages do not define or create law, but must be superseded and ended by it, when the issue is raised.
13. Government (prosecutors) must set an example of enforcing and obeying the laws. Case law to the same effect, e.g., Service v Dulles, 354 US 363; 77 S Ct 1152; 1 L Ed 2d 1403 (1957) and Glus v Eastern District Terminal, 359 US 231, 232; 79 S Ct 760, 762; 3 L Ed 2d 770, 772 (1959), which make clear that a plaintiff cannot rely on its own wrongdoing at the starting point of a process. This is a violation of due process.
The state in this case is relying on its own wrongdoing as the starting place of the process. An Arbitrary and Capricious Statute resulting in denial of Equal Protection and Due Process, Interstate Commerce protection and in violation of title 23, United States Code, Section 109(d) and Title 23, Code of Federal Regulations, Part 655.603; therefore the Supremacy Clauses of the Constitution.
WHEREFORE for all the foregoing reasons, and each of them individually, defendant moves that the Motion to Dismiss be granted with prejudice.
Signed, ___________________________
Floyd L. Phillips, Defendant
Attorney in pro per, Date __________


In 1966, Congress passed the HIGHWAY SAFETY ACT that required all traffic control on public roadways in the nation be based on sound engineering principles, practices and have a common "basis in fact" determination, appearance and application. These mandates are found in Title 23, United States Code, Section 109(d) and Title 23, Code of Federal Regulations (CFR), Part 655.601 through 655.603. In this Act’s remedy, Congress specifically preempted all state laws to facilitate the adoption of a uniform NATIONAL traffic control standard – The National Manual of Uniform Traffic Control Devices (MUTCD).
Title 23 655.603 Standards. Excerpts:
(a) National MUTCD. The MUTCD approved by the Federal Highway Administrator is the national standard for all traffic control devices installed on any street, highway, or bicycle trail open to public travel in accordance with 23 U.S.C. 109(d) and 402(a). The national MUTCD is specifically approved by the FHWA for application on any highway project in which Federal highway funds participate and on projects in federally administered areas where a Federal department or agency controls the highway or supervises the traffic operations.
(b) State or other Federal MUTCD. (1) Where State or other Federal agency MUTCDs or supplements are required, they shall be in substantial conformance with the national MUTCD. Changes to the national MUTCD issued by the FHWA shall be adopted by the States or other Federal agencies within 2 years of issuance. The FHWA Regional Administrator has been delegated the authority to approve State MUTCDs and supplements.
(2) The Direct Federal Program Administrator has been delegated the authority to approve other Federal agency MUTCDs with the concurrence of the Office of Traffic Operations. States and other Federal agencies are encouraged to adopt the national MUTCD as their official Manual on Uniform Traffic Control Devices.
(d) Compliance – (1) Existing highways. Each State, in cooperation with its political subdivisions, and Federal agencies shall have a program as required by Highway Safety Program Standard Number 13, Traffic Engineering Services (23 CFR 1204.4) which shall include provisions for the systematic upgrading of substandard traffic control devices and for the installation of needed devices to achieve conformity with the MUTCD.
(2) New or reconstructed highways. Federal–aid projects for the construction, reconstruction, resurfacing, restoration, or rehabilitation of streets and highways shall not be opened to the public for unrestricted use until all appropriate traffic control devices, either temporary or permanent, are installed and functioning properly. Both temporary and permanent devices shall conform to the MUTCD.
The Supremacy Clause provision under Article IV, Section 2 of the U.S. Constitution, providing that federal law is superior to and overrides state law when they conflict.
This Constitution, and the laws of the United States which shall be made in pursuance thereof; and all treaties made, or which shall be made, under the authority of the United States, shall be the supreme law of the land; and the judges in every state shall be bound thereby, anything in the Constitution or laws of any State to the contrary notwithstanding.
The theme throughout Title 23 clearly states "regardless of type or class or the governmental agency having jurisdiction".
MUTCD, 1A–2 – Requirements of Traffic Control Devices
This Manual sets forth the basic principles that govern the design and usage of traffic control devices. These principles appear throughout the text in discussions of the devices to which they apply, and it is important that they be given primary consideration in the selection and application of each device.

The Manual presents traffic control device standards for all streets and highways open to public travel regardless of type or class or the governmental agency having jurisdiction. Where a device is intended for limited application only, or for a specific system, the text specifies the restrictions on its use.
Most states adopted Title 23 mandates in a single sentence or paragraph without referencing Title 23 in the controlling state statute. For those states that have complied as advised under Title 23 and inserted the recommended federal language, the wording fails to convey its full meaning and importance; in many other states this language is decades old and referenced in, making it even less clear. This language is suggested – compliance is mandatory.
Therefore in many states such as Michigan, this authority is included administratively into state law and delegated to the state DOT by that state’s legislature and/or local authorities without mentioning this mandate and its volumes of guidelines, national standards and guiding canons of the engineering profession that must be followed. Because these professional standards have been incorporated by referenced into 23 CFR, they too are federal law.
Consequently, administrators in Michigan routinely certify compliance with the Title 23 to receive its benefits, while its far–reaching and comprehensive mandates remain virtually unknown to the legislators and every other political entity within the state exercising regulatory and policing powers. Resulting in widespread non–compliance with the law, confusion and chaos when the issue is raised!
Regardless of this oversight, they are nevertheless binding and there is no authority in Title 23 to post an invented numeric on official federal designated and regulated R2–1 traffic control device. Therefore, Michigan under the color of federal law is enforcing a state traffic control law that is not in compliance with the governing NATIONAL standard and its conditions precedent, equal protection and application requirement.
This federal law, Title 23 and its MUTCD is an ironic twist on federal government preemption. The drafters knew that safety is best served when the actual road being regulated is reviewed taking into account all factors. Traffic engineering studies are the cornerstone of basis–in–fact finding as to what traffic control devices or safety mitigation may be warranted. Because, without a study, all traffic control is based on unfounded conjecture and safety is compromised.
The Michigan Department of Transportation is well versed in the Title 23 requirements, in fact, is a well respected contributor to the National discourse and finding–of–fact. The agency to the best of its abilities tries to convey to Michigan’s Executive and Legislative Branches of Government its duties under federal law, but it is not always successful; at the end of the day, this agency is subservient and follows the laws of the state as directed. In this case, the laws adopted by the Legislature are in conflict with controlling federal regulations.
Notwithstanding, this Federal law says according to LOCAL conditions, after engineers have personally determined how the people who use that particular section of highway are driving and they have reviewed the highway facilities, existing traffic control devices and accident data. Then they are directed to apply nationally accepted and verified sound engineering practices to remedy any problems and best manage the flow for the conditions found – not conjecture from Washington, State Capitals or Local Politicians.
Congress granted itself special powers in response to a national crisis not otherwise contained in the law when they adopted the NMSL (National Maximum Speed Limit). When the federally mandated NMSL was repealed in 1995, state politicians wrongly assumed that this failed policy of setting arbitrary limits was a political issue deferred to them.
This simply isn’t the case; the repeal returned the nation to prior law. This law has matured and authorization for a locality or state agency to use a federally regulated “official traffic control device” is contingent upon full compliance with the Code of Federal Regulations and its MUTCD. It no longer allows the use of regulatory traffic control devices to post politically invented numbers.
The aforesaid federal law, controls traffic regulation on all streets and highways. Pursuant to that law, there is a federal Manual for Uniform Traffic Control Devices (MUTCD). The MUTCD sets conditions precedent for traffic control. It requires states and local authorities to identify pre–existing problems, do valid engineering studies, and only impose that minimal amount of traffic control as solves the pre–identified problem, without causing any new problem nor safety impairment.
"MUTCD: Frequently Asked Questions

The FHWA publishes the MUTCD, but who decides which traffic control devices are selected and installed?
Although the FHWA adopts the standards, the individual State and local highway agencies, not the FHWA, select, install, operate, and maintain traffic control devices on all roadways (including the Interstate and the U.S. numbered systems) nationwide.
The above cites clearly show that Speed Limit Signs (R–1) are federally regulated devices that Michigan is authorized to post, providing the required conditions precedent are met (federal standards). The federally mandated shape and color of regulatory speed limit signs are of common knowledge; rectangle in shape, white reflective field, black legend and border trim. Less known, these same regulations contain conditions precedent for establishing the value of the NUMERIC displayed.
The National MUTCD section 2B–10, “Speed Limit Sign” federal designation R2–1, is a regulatory safety device; therefore, the numeric value “shall” “be determined on basis of an engineering study” finding that determined a need exist for that particular section of highway. The SHALL is mandatory language – basis–in–fact traffic engineering study with conditions precedent having been met.
A study is a finding – in engineering practices it is a written report kept on file for that particular section of highway. This study is required for all highways, including those where no speed limit has been determined to be warranted. The prevailing speeds and trends as measured for that particular section of highway is what determines the design speeds of that facility’s traffic control devices and structures, this fact based finding must be articulated and recorded for others to reference in order to obtain the desired safety objectives.
“MUTCD: Engineering Study — the comprehensive analysis and evaluation of available pertinent information, and the application of appropriate principles, Standards, Guidance, and practices as contained in this Manual and other sources, for the purpose of deciding upon the applicability, design, operation, or installation of a traffic control device. An engineering study shall be performed by an engineer, or by an individual working under the supervision of an engineer, through the application of procedures and criteria established by the engineer. An engineering study shall be documented.”
Clearly the definition of an Engineering Study in Title 23 does not extend Engineering Judgement to Political Entities or Chiefs of Police, therefore the underlined section R 28.1125 Sec. 2.25. is also void.
R 28.1125 Sec. 2.25. Traffic engineer. The office of traffic engineer is hereby established. The traffic engineer shall be appointed in a manner prescribed by the ordinance making body and shall exercise the powers and duties provided in this code in a manner which is consistent with prevailing traffic engineering and safety practices and which is in the best interests of this governmental unit. If a traffic engineer is not appointed, the authority of such engineer shall be vested in the chief of police.
Below are portions of engineering practices that are referenced into the federal manual in regards to establishing an appropriate speed numeric, an engineer’s judgement must include such verified practices and profession tenets when they are formulating the engineering studies findings.
"If these values are based on a speed limit that does not reflect the prevailing speed of traffic, safety may be compromised."
In these few words the reasons that engineering studies are crucial for safety is well stated - the basis for all traffic control originates with this finding, the timing traffic signals, length of no passing zones, need for curve warnings, distance to hazards and size of signs etc.. Establishing arbitrary limits without a finding, increases accident rates and setting them on the basis an engineering study reduce them. To wit, making sure that traffic control devices reflect the actions of the motorists using that particular section of highway.
Words to the same effect are emphasized in every nationally recognized traffic engineering standard or guideline. Here is how California’s state traffic manual states it;
Chapter 8–13, California State Traffic Manual:
"Speed limits established on the basis of the 85th percentile conform to the consensus of those who drive highways as to what speed is reasonable and prudent, and are not dependant on the judgement of one or a few."
"Further studies have shown that establishing a speed limit at less than the 85th percentile (Critical Speed) generally results in an increase in accident rates."
Washington State DOT website:
"people don't automatically drive faster when the speed limit is raised, speed limit signs will not automatically decrease accident rates nor increase safety, and highways with posted speed limits are not necessarily safer than highways without posted limits.
As illustrated in the above Washington state quote, speed limits are not required within sound engineering practices, the MUTCD or federal laws; in–fact, there are contemporary real world examples where safety results have been favorable without them and deserve more research (i.e. Montana until July 1999 and the Autobahn with lower than US fatality rates for comparable highways). Therefore the use must be justified by a study, and likewise there is no authority whatsoever granted in the MUTCD to post an invented numeric. The mandated basis–in–fact finding must first determine that a need exist, and that this device is the proper remedy to address it by reducing unacceptable germane accident rates, and it has an engineering fact–based expectation of accomplishing this objective.
The MUTCD admonishes engineers not use a device unless it will have the basis–in–fact desired effect and is warranted for that particular section of highway. Engineers have found that motorists on the whole will drive at the speed they rightly feel is safe regardless of the posted limit, and when signage is warranted for safety reasons the motorists cannot differentiate between devices placed for other reasons. Therefore, these federal laws require local review of the particular section of highway being regulated with specific conditions precedent governing the use of each device.
"2b–10 Speed Limit Sign
The Speed Limit sign shall display the limit established by law, or by regulation, after an engineering and traffic investigation has been made in accordance with established traffic engineering practices. The speed limits shown shall be in multiples of 5 miles per hour.

In order to determine the proper numerical value for a speed zone on the basis of an engineering and traffic investigation the following factors should be considered.
1. Road Surface characteristics, shoulder condition, grade, alignment and sight distance.
2. The 85–percentile speed and pace speed.
3. Roadside development and culture, and roadside friction.
4. Safe speed for curves or hazardous locations within zone.
5. Parking practices and pedestrian activity.
6. Reported accident experience for a recent 12 month period.

Here in the first paragraph of the adopted federal regulations "an engineering and traffic investigation" is required. No required investigation was done to establish a legal numeric value on this section of highway. The second paragraph uses the phrase "on the basis of an engineering and traffic investigation" to list those items that are contained in an investigation.
Nevertheless, "established traffic engineering practices" are those outlined, accepted or recommended by AASHTO, FHWA and the ITE and they are included by reference in this federal law. Here are a few examples;
FHWA (Federal Highway Administration)
Report No. FHWA/RD–85/096
Technical Summary, "Synthesis of Speed Zoning Practice" which states:
"Based on the best available evidence, the speed limit should be set at the speed driven by 85 to 90 percent of the free–moving vehicles rounded up to the next 5 MPH increment. This method results in speed limits that are not only acceptable to a majority of the motorist, but also fall within the speed range where accident risk is lowest. Allowing a 5 MPH tolerance, enforcement would be targeted at drivers who are clearly at risk.
No other factors need to be considered since they are reflected in the drivers speed choice. If there are unusual hazards not readily apparent to drivers, then a warning sign could be installed giving the nature of the hazard and, if necessary, supplemented with a realistic advisory speed."
A 1969 "Resolution of the annual meeting of the American Association of State Highway Officials" states:
"The review of existing practices revealed that most of the member departments use, primarily, the 85th percentile speed. Some agencies use the 90th percentile speed, and of secondary consideration are such factors as design speed, geometric characteristics, accident experience, test run speed, pace, traffic volumes, development along the roadway, frequency of intersections, etc."
"On the basis of the forgoing review, the Subcommittee on Speed Zoning recommends to the AASHTO Operating Committee on Traffic for consideration as an AASHTO Policy on Speed Zoning that:
The 85th percentile speed is to be given primary consideration in speed zones below 50 miles per hour, and the 90th percentile speed is to be given primary consideration in establishing speed zones of 50 miles per hour or above. To achieve the optimum in safety, it is desirable to secure a speed distribution with a skewness index approaching unity"
Institute Of Transportation Engineers
ITE Committee 4M–25, Speed Zone Guidelines:
"Thus, the overriding basis (from a safety perspective) for speed zoning should be that the creation of the zone, and the speed limit posted, results in an increase in the percentage of motorists driving at or near the 85th percentile speed."
"A third rationale is the need for consistency between the speed limit and other traffic control devices. Signal timing and sight distance requirements, for example, are based on the prevailing speed. If these values are based on a speed limit that does not reflect the prevailing speed of traffic, safety may be compromised."
"2. The speed limit within a speed zone shall be set at the nearest 5 MPH increment to the 85th percentile of free flowing traffic or the upper limit of the pace of the 10 MPH pace." "In no case should the speed limit be set below the 67th percentile speed of free flowing traffic."
In each of the above examples accepted engineering practices are based on findings of studies that have been examined scientifically, peer reviewed and field tested prior to acceptance as fact. Under the MUTCD charter, applying these national recognized findings to meet a particular section and classification of highway needs is how engineers are directed to determine what weight is given to each component of a study. There are core components that have become absolute for all studies. Listed in the attached memorandum are the core considerations that must be measured and applied along with excerpts from the studies that are most applicable and accepted as factual for this classification of highway.
The attached Memorandum contains an OVERVIEW OF TERMS, STANDARDS AND PRACTICES. This attachment is a synthesis of the most current engineering positions on each of the issues.
Since 1944, when the State of Michigan placed a speed limit sign to regulate traffic on a federally funded highway, each OFFICIAL TRAFFIC CONTROL DEVICE was purported to have been installed in full compliance with the then current federal laws – National MUCTD which originated in the 1920’s. In 1966 this was expanded to all roadways open to the public.
The supremacy of the Code of Federal Regulations (CFR) over local conflicting statutes can not be disputed and any arguments by the state that proclaim supremacy of state statutes or county ordinances over federal law is unconstitutional on its face.