Addressing Liability Issues of Proactive Safety Improvements (2026)
Chapter: VII. EXISTING LAWS, ADMINISTRATIVE RULES, AND IMMUNITIES
VII. EXISTING LAWS, ADMINISTRATIVE RULES, AND IMMUNITIES
This section identifies administrative rules, internal practices, state laws, and legal immunities that are used by state agencies to defend dangerous condition claims. While few of the passages specifically analyze the use of predictive or cumulative data by the agency, the concepts can be borrowed to form the basis of legislation and rules that could be supported by the agency and may be used to limit the use of cumulative predictive data in tort actions.
A. Federal and State Laws
The researchers have included state and administrative rules as well as legal doctrines that could provide the transportation agency with protection from liability as a matter of law in this section. The section includes both federal law and state statutes from Georgia, Washington, and Pennsylvania, and an administrative rule from Oregon. The protections outlined can be used as the basis for a model statute, rule, or for internal guidance, depending on the interest of the DOT in promoting such legislation or other practices.
The section also includes a discussion on statutory immunities including sovereign immunity, official and discretionary immunity, and the deliberative process immunity. This discussion could be used as a basis for the introduction to those immunities for states that do not currently enjoy them and as talking points with the legislative bodies of those states.
B. Engineering Judgment Application Incorporated in the Law
Engineering judgment, or the application of engineering concepts, applied with the education and experience of the engineer, is the basis of most design and operational decisions relating to transportation and traffic control. The MUTCD includes an extensive discussion of the concepts of engineering judgment and its application.
The MUTCD130 was adopted as a regulation by reference in 23 U.S.C., section 109(d) and 23 C.F.R., section 655.603 in December 2023. According to the FHWA, the MUTCD is “the law governing all traffic control devices. Non-compliance with the MUTCD ultimately can result in the loss of federal-aid funds as well as in a significant increase in tort liability.”131 It is the national standard for designing, applying, and planning traffic control devices and applies to all roads and streets in the United States.132
This text is taken directly from the 2024 MUTCD:
The decision to use a particular device at a particular location should be made on the basis of either an engineering study or the application of engineering judgment. Thus, while this Manual provides Standards, Guidance, and Options for design and applications of traffic control devices, this Manual should not be considered a substitute for engineering judgment. Engineering judgment should be exercised in the selection and application of traffic control devices, as well as in the location and design of roads and streets that the devices compliment.133
C. Engineering Judgment and Case-by-Case Flexibility
The MUTCD defines engineering judgment as a fundamental principle which is to be used in implementing traffic control devices. Engineers are encouraged to use real-world data, traffic patterns, and their knowledge of the behavior of the traveling public to guide decisions used to address traffic control.
Since it is incorporated in federal law, the MUTCD must be considered by state DOTs as they develop permanent traffic control plans, work zone plans and other traffic control requirements. The states are obligated to:134
1. Adopt the MUTCD or Manual in Substantial Conformance
Each state must adopt an MUTCD for that state and the basis for the MUTCD is defined in each state’s transportation law. A state has the option of: Adopt the federal MUTCD as its MUTCD (as 18 states, such as Arkansas do), Adopt the federal MUTCD with a state supplement (22 states, along with Puerto Rico and DC, take this approach), or
Develop and adopt its own state MUTCD (10 states, including Texas, have developed state manuals)
A state supplements or state MUTCD must be in “substantial conformance” with the federal MUTCD and must be approved by the FHWA prior to adoption. When the MUTCD is revised or updated, States have two years to adopt the new version or adopt an updated State MUTCD.
2. Comply with New Standards
When changes in the MUTCD apply to existing TCDs in the field and are deemed to be of critical safety importance, states are given compliance dates for updating devices. The current MUTCD provides target compliance dates in Table I-2 of the introduction.
If a compliance date isn’t provided, FHWA notes that:
Each State, in cooperation with its political subdivisions, is required by Federal law (23 U.S.C. 402(a)) to have a program for the systematic upgrading of substandard traffic control devices and for the installation of needed devices to achieve conformity with the MUTCD. The program should include dedicated time to properly assess traffic control operations and needs, budgeting of funds required for implementing MUTCD changes and, to the extent possible, and accomplishing the changes either when the devices are no longer serviceable because they reach the end of their service
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130 FHWA, Frequently Asked Questions—General Questions on the MUTCD, MANUAL ON UNIFORM TRAFFIC CONTROL DEVICES (MUTCD), https://mutcd.fhwa.dot.gov/knowledge/faqs/faq_general.htm#genq3 (last visited Jan. 14, 2025).
131 FHWA, Overview, MANUAL ON UNIFORM TRAFFIC CONTROL DEVICES (MUTCD), https://mutcd.fhwa.dot.gov/kno-overview.htm (last visited March 2, 2026).
132 23 C.F.R. § 655.603.
133 MUTCD § 1A.09.
134 Kittleson LLC, Legal Aspects of the MUTCD, MUTCD RESOURCES FOR PRACTITIONERS & ATTORNEYS, https://mutcd.kittelson.com/legal-aspects-of-the-mutcd/ (last visited Jan. 14, 2025).
life or otherwise need to be replaced, or when other events such as highway improvement or reconstruction projects occur.”135
3. Use the MUTCD
State and local transportation engineers and planners use the MUTCD to inform the design, placement and construction of TCDs. The MUTCD provides mandates of varying levels that inform this process.136
The MUTCD states:
“The decision to use a particular device at a particular location should be made on the basis of either an engineering study or the application of engineering judgment. Thus, while this Manual provides Standards, Guidance, and Options for design and applications of traffic control devices, this Manual should not be considered a substitute for engineering judgment. Engineering judgment should be exercised in the selection and application of traffic control devices, as well as in the location and design of roads and streets that the devices compliment.”137
The importance placed on a qualified traffic engineer to make sound engineering judgments in the selection and implementation of TCDs cannot be overlooked or dismissed. There are infinite varieties of roadway and intersection designs and there is no “one size fits all” mentality in the application of TCDs. The proper use and application of the MUTCD starts with the decisions made by a qualified traffic engineer.138
Practice note: Most states have not chosen to adopt the MUTCD via regulation or administrative rule, instead deciding to incorporate the provisions, or guidance that are in substantial compliance with those provisions using internal publications or via their agency’s guidance.
The MUTCD is a model of flexibility and has very few “shall” conditions. The basis of a “uniform” system is the use of clear communication to the road user. “Uniformity and consistency in message, placement, and operation of traffic control devices have been shown to accommodate the expectancy of the road user.”139
As noted, phased implementation of changes is expected and a state or other governing authority has discretion and flexibility to implement changes over time. Documentation of the plan to implement any changes, especially if it is costly and will take a number of years, is key to keeping the agency on track for compliance with the 2024 edition. The implementation plan will also assist the agency in explaining its timeframe, should that become an issue in litigation.
D. Immunity for Compliance with Industry Guidance
In Georgia, the state DOT has been granted limited immunity for liability in cases where an engineering plan is prepared in compliance with industry regulations at the time of the plans preparation. The statute reads as follows:
Exceptions to state liability
The state shall have no liability for losses resulting from:
. . . .
(10) The plan or design for construction of or improvement to highways, roads, streets, bridges, or other public works where such plan or design is prepared in substantial compliance with generally accepted engineering or design standards in effect at the time of preparation of the plan or design[.]140
The court considered this statute in Sadler v. Dep’t of Transp.,141 after plaintiff’s decedent filed suit against the agency claiming that GDOT was negligent in failing to place adequate markings and signs in at the intersection of Cassidy Road and Georgia State Highway 38. Plaintiffs alleged that the lack of sufficient striping and signing created a condition that confused drivers and caused a fatal accident.
The driver testified that she stopped at the stop sign on Cassidy Road before entering the median area of the bypass, and that once she entered the median, she stopped at the painted stop-bar to assess the oncoming traffic before proceeding across the remainder of the bypass.
According to the driver, a car in a left-hand turn lane partially blocked her view of oncoming traffic while she was stopped. She further testified that a passenger helped her determine when to enter the intersection, and that her vehicle was struck on the passenger side by an oncoming vehicle.
The state defended the claim arguing the design of the intersection complied with the MUTCD in effect at the time the intersection was designed. The plaintiff’s experts testified that additional signing was necessary to comply with the MUTCD. However, the court reasoned that since the MUTCD specified that stop or yield signs “may” be placed in the median if it was more than 30 feet wide, said signs were permissive, rather than mandatory.
The court found that the design of the intersection complied with the provisions in the MUTCD that were in effect at the time of the construction of the intersection and granted the DOT’s motion to dismiss. The ruling was upheld on appeal.
Official or Discretionary Immunities
Kansas Tort Claims Act includes several defenses that are helpful to the agency in its defense of tort claims.142 Most applicable to this digest is section (a) (13) which provides a defense based upon the use of generally accepted guidance implemented at the time of design as set out in the following:
(a) A governmental entity or an employee acting within the scope of the employee’s employment shall not be liable for damages resulting from:
. . . .
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135 Id. (citing FHWA MUTCD site FAQs, (October 2011)) (emphasis added in this digest).
136 Id. (citing Number 4 on Using the MUTCD, https://mutcd.kittelson.com/mutcd-basics/using-the-mutcd/).
137 MUTCD § 1A.09.
138 MUTCD § 1A (2024).
139 See, 23 C.F.R. § 655.603 (summary of 2023 final rule).
140 GA. CODE § 50-21-24 (2024) (emphasis added).
141 716 S.E.2d 639 (Ga. Ct. App. 2011).
142 KAN. STAT. ANN. § 75-6104 (2024).
(5) any claim based upon the exercise or performance or the failure to exercise or perform a discretionary function or duty on the part of a governmental entity or employee, whether or not the discretion is abused and regardless of the level of discretion involved;
. . . .
(8) the malfunction, destruction or unauthorized removal of any traffic or road sign, signal or warning device unless it is not corrected by the governmental entity responsible within a reasonable time after actual or constructive notice of such malfunction, destruction or removal. Nothing herein shall give rise to liability arising from the act or omission of any governmental entity in placing or removing any of the above signs, signals or warning devices when such placement or removal is the result of a discretionary act of the governmental entity;
. . . .
(11) the failure to make an inspection, or making an inadequate or negligent inspection, of any property other than the property of the governmental entity, to determine whether the property complies with or violates any law or rule and regulation or contains a hazard to public health or safety;
(12) snow or ice conditions or other temporary or natural conditions on any public way or other public place due to weather conditions, unless the condition is affirmatively caused by the negligent act of the governmental entity;
(13) the plan or design for the construction of or an improvement to public property, either in its original construction or any improvement thereto, if the plan or design is approved in advance of the construction or improvement by the governing body of the governmental entity or some other body or employee exercising discretionary authority to give such approval and if the plan or design was prepared in conformity with the generally recognized and prevailing standards in existence at the time such plan or design was prepared[.]143
Practice note: The time frame of the design may be important to the defense of a future claim. A plan to maintain copies of the guidance in place at the time should be made when intersection, geometric and other plans are drawn.
Pennsylvania Law on Placement and Use of Traffic Control Measures
The need for the application of engineering judgment during the decision-making process is codified in Pennsylvania law as relates to the selection of traffic control devices:
(a) General. This chapter applies to the approval, location, installation, revision, operation, maintenance and removal of all traffic signs, signals, markings and other traffic-control devices on all streets and highways in this Commonwealth. All signs, signals, markings and other traffic-control devices erected shall conform to this chapter. Traffic restrictions, which were posted or erected prior to February 4, 2006, in accordance with any regulations in effect at that time, are not subject to this chapter.
(b) New restrictions . . . engineering and traffic studies can be performed by police officers, roadmasters, maintenance supervisors or traffic technicians. The establishment or revision of a traffic restriction may be warranted if one of the following applies:
(1) One or more of the engineering and traffic study warrants covered in this chapter justifies the traffic restriction.
(2) Sound engineering judgment based upon a combination of all data sources substantiates the need for the restriction.
(c) Removal of an existing restriction. The removal of an existing traffic restriction may be warranted if one of the following applies:
(1) A study indicates that none of the engineering and traffic study warrants covered in this chapter justify the existing traffic restriction.
(2) The condition that originally justified the restriction no longer exists.
(d) Warrants no substitute for engineering judgment. Warrants established under this chapter provide the threshold for consideration of the installation of a traffic-control device, but are not a substitute for engineering judgment. The fact that a warrant for a particular traffic-control device is met is not conclusive justification for the installation of the device.144
E. Prioritization of Projects
Washington DOT state law requires prioritization of transportation projects.145
Declaration of purpose.
The legislature finds that solutions to state highway deficiencies have become increasingly complex and diverse and that anticipated transportation revenues will fall substantially short of the amount required to satisfy all transportation needs. Difficult investment trade-offs will be required.
It is the intent of the legislature that investment of state transportation funds to address deficiencies on the state highway system be based on a policy of priority programming having as its basis the rational selection of projects and services according to factual need and an evaluation of life-cycle costs and benefits that are systematically scheduled to carry out defined objectives within available revenue. The state must develop analytic tools to use a common methodology to measure benefits and costs for all modes. . . .
Oregon Administrative Rule
In Oregon, direction to use the Highway Safety Manual process, along with the predictive model discussed therein, is incorporated in an administrative rule relating to access management. The rule also requires documentation of the decision-making process used by professional staff. Implemented in 2012, the rule reads in pertinent part:146
Access Management in Project Delivery
(1) Applicability:
(a)This rule applies to access management in the project delivery process for modernization and highway improvement projects included in the Statewide Transportation Improvement Program
. . . .
(4) Content of an Access Management Strategy
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143 Id. (emphasis added).
144 67 PA. CODE § 212.4 (2025) (emphasis added).
145 WASH. REV. CODE § 47.05.010
146 OR. ADMIN. R. 734-051-5120 (2012) (emphasis added).
