Tansavatdi v. City of Rancho Palos Verdes

Filed 9/24/26 CERTIFIED FOR PUBLICATION IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA SECOND APPELLATE DISTRICT DIVISION FOUR BETTY TANSAVATDI, B343512 Plaintiff and Appellant, (Los Angeles County Super. Ct. No. BC633651) v. CITY OF RANCHO PALOS VERDES, Defendant and Respondent. APPEAL from a judgment of the Superior Court of Los Angeles County, David K. Reinert, Judge. Affirmed. Mardirossian Akaragian, Armen Akaragian and Adam Feit; Singleton Schreiber and Benjamin I. Siminou for Plaintiff and Appellant. Wesierski & Zurek and David M. Ferrante; Pollak, Vida & Barer, Karen M. Stepanyan and Daniel P. Barer for Defendant and Respondent.  INTRODUCTION Under Government Code section 830.6,1 public entities may be immune from tort liability for dangerous conditions “caused by the plan or design” of public property. This protection, afforded to public bodies for the construction of public infrastructure, is generally called “design immunity.” In a prior opinion in this case, our Supreme Court reaffirmed the longstanding rule that design immunity does “‘not necessarily shield the state from liability for a failure to warn of the same dangerous condition.’” (Tansavatdi v. City of Rancho Palos Verdes (2003) 14 Cal.5th 639, 657 (Tansavatdi I).)2 The Supreme Court explained that, if, for example, a design for a roadway created a dangerous traffic condition, design immunity might shield a public entity from liability for creating the dangerous traffic condition. But design immunity does not necessarily immunize the public entity from failing to warn the public of it. (Id. at pp. 658–659.) The Supreme Court’s prior opinion expressly left open the following question: “whether design immunity might apply if the public entity is able to show that the presence or absence of warning signs was part of the approved design.” (Tansavatdi I, supra, 14 Cal.4th at p. 661.) In other words, the Supreme Court has not yet resolved whether and how design immunity applies when warning signs about a danger are themselves part of an 1 Undesignated statutory references are to the Government Code. 2 Design immunity requires that a public entity establish three elements: “‘(1) a causal relationship between the plan or design and the accident; (2) discretionary approval of the plan or design prior to construction; and (3) substantial evidence supporting the reasonableness of the plan or design.’” (Tansavatdi I, supra, 14 Cal.5th at p. 653.) 2 approved public design. Following further proceedings in the trial court, that question is now squarely before us. We hold as follows. When (a) the public entity has provided some warning of the allegedly dangerous condition, and (b) that warning was included as part of a reasonable plan or design that would be otherwise entitled to design immunity under section 830.6, then (c) design immunity may apply. In our view, there is an important distinction between cases in which the public entity has provided no warning at all of the dangerous condition, and cases (like this one) in which the public entity has provided some warning of the allegedly dangerous condition—but a plaintiff alleges the warning was insufficient. Complaints about the adequacy of an existing warning approved as part of a government’s design for public infrastructure are, in essence, complaints about the government’s design of the warning. Such complaints fall into the area where design immunity has long applied. Applying this reasoning to the facts of the case, we affirm the trial court’s grant of summary judgment. We also affirm the trial court’s award of expert fees to the respondent, the City of Rancho Palos Verdes. FACTUAL AND PROCEDURAL HISTORY This case arises from a tragic death. In 2016, Jonathan Tansavatdi was killed when his bicycle collided with a turning truck at an intersection in the City of Rancho Palos Verdes. Jonathan’s mother, Betty Tansavatdi,3 sued the City alleging that the accident resulted from a dangerous condition of public property under section 835. Tansavatdi contended that the City was 3 We refer to Jonathan by first name for clarity, as he shares a surname with the plaintiff. No disrespect is intended. 3 liable for creating a dangerous condition in designing the roadway and in failing to adequately warn of that danger. While the factual record is extensive and the procedural history lengthy, we resolve the bulk of the appeal based on an issue of immunity. Our discussion is therefore focused on the record relevant to that issue. A. The Accident The facts surrounding the accident are largely undisputed. On the afternoon of March 18, 2016, Jonathan was riding his bicycle on Hawthorne Boulevard in the City. Although most of Hawthorne includes a bicycle lane, the bicycle lane stops at Dupre Drive (to the north of the intersection at issue) and then restarts after Vallon Drive (the intersection at issue). The block between Dupre and Vallon pitches sharply downhill in the southbound direction and curves to the right. (Tansavatdi I, supra, 14 Cal.5th at p. 648.) There is a right-turn-only lane on southbound Hawthorne at the intersection with Vallon. (Ibid.) At the time of the accident, Jonathan was traveling south (downhill) along the right side of Hawthorne. (Tansavatdi I, supra, 14 Cal.5th at p. 649.) As he approached the intersection with Vallon, he rode his bicycle into the right turn lane. But rather than turn right onto Vallon, he continued riding straight through the intersection. As Jonathan entered the intersection, an 80-foot tractor trailer was making a right turn from Hawthorne onto Vallon. Due to the length of the trailer, the truck started its turn to the left of the right turn only lane, causing it to cut across the right turn lane at a perpendicular angle. Jonathan collided with the truck and died from his injuries. (Ibid.) The truck driver testified that he was stopped at the red light at Vallon with his right turn signal on, with his truck straddling the right lane and the 4 right turn only lane. He then slowly began his turn onto Vallon. He checked his mirrors as he did so, but did not see anyone. A witness who turned onto southbound Hawthorne after seeing Jonathan bike past testified that Jonathan was traveling an estimated 35 to 40 miles an hour. She followed behind Jonathan in the right lane, but she moved to the left lane when she saw the truck in the right lane with his right turn signal on, waiting at the red light at Vallon. She testified that as she came down the hill, the light at Vallon turned green and the truck started its right turn. She noticed that Jonathan, who was still in the right lane, had not slowed down, so she began honking her horn to get his attention. The witness recalled that when Jonathan was about 40 feet from the turning truck he looked up and attempted to stop. He slowed to about 10 to 15 miles per hour before hitting the side of the truck. B. Tansavatdi’s Complaint Tansavatdi filed a complaint against the City and others alleging a single cause of action for dangerous condition of public property pursuant to section 835.4 The complaint alleged that the intersection of Hawthorne and Vallon constituted a dangerous condition the City had “created or allowed to be created” under section 835. The complaint further alleged the City had provided “inadequate warning of dangerous conditions not reasonably apparent to motorists” driving through that intersection. As discussed below, that the intersection itself constituted the allegedly dangerous condition is significant to our resolution here. 4 Tansavatdi also sued other governmental entities, the driver of the truck, and the trucking company. Only the City is pertinent to this appeal. 5  C. First Motion for Summary Judgment The City moved for summary judgment, focused on Tansavatdi’s theory that the absence of a bicycle lane on Hawthorne north of Vallon constituted a dangerous condition. The City asserted the affirmative defense of design immunity under section 830.6. (Tansavatdi v. City of Rancho Palos Verdes (2021) 60 Cal.App.5th 423, 429, review granted Apr. 21, 2021, S267453 (Tansavatdi v. City).) “In support of its claim for design immunity, the city submitted plans for a 2009 street resurfacing project (2009 plans), which included the resurfacing and restriping of Hawthorne Boulevard. Among other specifications, those plans included directions to install specific striping details, pavement markings, and signs.” (Tansavatdi v. City, supra, 60 Cal.App.5th at p. 429.) The City also filed a declaration and deposition excerpts from Nicole Jules, a former senior engineer and deputy director of public works for the City. “Jules testified that in 2009, the city had carried out a resurfacing project that included Hawthorne Boulevard. She explained that the project relied on federal funding, and that the city was required to submit plans signed by the city to secure that funding.” (Tansavatdi v. City, supra, 60 Cal.App.5th at p. 430.) “Regarding the site of the accident and the portion of Hawthorne Boulevard preceding it, Jules opined that it met or exceeded all applicable government standards, and that the 2009 plans, including the absence of a bicycle lane, were reasonably approved.” (Id. at p. 431.) The conclusion that the 2009 plans were reasonable and in compliance with applicable guidelines was echoed by Rock Miller, the City’s traffic engineering expert. (Ibid.) 6  The trial court granted summary judgment for the City based on design immunity. The court found that the City had established the elements of design immunity as a matter of law—a causal relationship between the design and the accident, the relevant City employee's discretionary approval of the 2009 plans, and substantial evidence that the plans were reasonable. (Tansavatdi v. City, supra, 60 Cal.App.5th at p. 433.) The trial court did not address Tansavatdi’s failure to warn claim. (Ibid.) On appeal, Tansavatdi argued that design immunity did not protect the absence of a bicycle lane and, alternatively, that her failure to warn theory should survive the application of design immunity. (Tansavatdi v. City, supra, 60 Cal.App.5th at p. 433.) This court affirmed the trial court’s finding that the City established the elements of design immunity as to the absence of a bicycle lane at the site of the accident. (Id. at pp. 435–441.) We also considered Tansavatdi’s failure to warn claim, specifically, that “the absence of a bicycle lane at the area of the accident constituted a concealed trap for which a warning was necessary.”5 (Id. at p. 441.) We concluded that “design immunity does not, as a matter of law, preclude liability under a theory of failure to warn of a dangerous condition.” (Ibid.) We remanded the case for 5 A failure to warn claim may also be subject to signage immunity under section 830.8, which precludes liability “for an injury caused by the failure to provide traffic or warning signals, signs, markings or devices.” As we discuss further below, the “concealed trap” exception to signage immunity allows for liability for injury “‘caused by such failure if a signal, sign, marking or device ... was necessary to warn of a dangerous condition which endangered the safe movement of traffic and which would not be reasonably apparent to, and would not have been anticipated by, a person exercising due care.’” (§ 830.8; see also Tansavatdi I, supra, 14 Cal.5th at p. 654.) We do not reach signage immunity or the concealed trap exception here, because we conclude the relevant warnings were protected by the City’s design immunity. 7 the trial court to consider the failure to warn theory in the first instance. (Id. at p. 442.) The Supreme Court granted the City’s petition for review. In Tansavatdi I, supra, 14 Cal.5th at page 647, the court held that “design immunity does not categorically preclude failure to warn claims that involve a discretionarily approved element of a roadway.” The Supreme Court accordingly affirmed the decision in Tansavatdi v. City and remanded the matter so that Tansavatdi’s failure to warn claim could be considered by the trial court. (Tansavatdi I, supra, 14 Cal.5th at p. 670.) But the court noted that the City had not proffered evidence of whether City officials considered whether to include warnings about the alleged dangerous condition as part of its design plan. Thus, the court cautioned, “we have no occasion to consider, and express no view on, how design immunity might affect a failure to warn claim when a public entity does produce evidence that it considered whether to provide a warning.” (Id. at p. 661.) D. Second Motion for Summary Judgment 1. City’s Motion Upon remand, the City filed a new motion for summary judgment focused on the issue left open by the Supreme Court in Tansavatdi I. Specifically, the City argued that it had expressly considered the signs and pavement markings that were present at the time of the accident, and it included those warnings as part of the 2009 plans. Thus, the City contended the warnings were subject to design immunity under section 830.6. Alternatively, the City argued that even if design immunity was inapplicable, there was no triable issue as to the elements of a failure to warn claim. The City argued that there was no dangerous condition as a matter of law (citing evidence of an absence of other accidents), the City had no notice 8 of any such condition, there was no evidence of a concealed trap, the City provided warnings of the purportedly dangerous condition of the roadway, and the absence of additional warnings was not a substantial factor in the accident. In support of its motion, the City presented evidence of the warning signs and markings on Hawthorne to the north of the intersection with Vallon. These warnings included broken striping for 200 feet in advance of the preceding intersection (Dupre and Hawthorne) to signal the end of the bicycle lane. In the center median, about 500 feet south of Dupre, there was a yellow curve warning sign showing a curved arrow, and below that a 35 miles per hour advisory plate. Adjacent to these signs were “35” markings stenciled in white on the pavement in each lane. Miller, the City’s engineering expert, testified about the California Manual on Uniform Traffic Control Devices (MUTCD), the standard for design decisions regarding traffic controls. Miller explained that the curve warning signs were advised by the MUTCD where the comfortable speed around a curve (here, 35 miles per hour) was lower than the speed limit (45 miles per hour). At the same location, on the right shoulder, there was a yellow pictorial sign showing a truck on a steep grade and below that a sign indicating an “8% GRADE.” These signs were located approximately 225 feet from the start of the right- hand curve, which begins about 700 feet south of Dupre. Along the curve in the median were posted six yellow and black chevron signs, spaced equally. Miller explained that these signs are recommended under the MUTCD because the comfortable speed posted around the curve was ten miles per hour lower than the speed limit. About 570 feet north of Vallon, there was a warning sign depicting a traffic signal ahead, as well as “SIGNAL AHEAD” messages stenciled on the pavement in each lane. According to Miller, these 9 warnings are recommended under the MUTCD because the traffic signal is not visible to approaching traffic due to the curve. This area also included a flashing yellow beacon in the median about 550 feet north of Vallon, near one of the chevron signs. Finally, the right turn lane was marked with striping beginning 220 feet north of Vallon, with painted arrows on the pavement. There were also two “RIGHT LANE MUST TURN RIGHT” signs, one near the start of the turn lane and one about 100 feet from the intersection. Miller opined that all of these signs and markings were in conformance with the MUTCD. Miller also opined that the intersection and approach were safe when used with reasonable due care and were in compliance with all applicable government standards. The City presented evidence that the marking and signs identified were part of the construction plans for the City’s 2009 street resurfacing project. Former employee Jules provided a declaration stating that at the time of the 2009 project, “the city considered what signage, striping and stenciling to include on Hawthorne Boulevard regarding the bike lane and any other warnings, and those were included in the final plans and installed or kept in accordance with the plans.” She stated that the warning signs described above were already in place in 2009 and the “2009 plans expressly acknowledged existed and consciously chose to keep them in place, making their retention part of the 2009 approved plans.” Miller noted that between 2022 and 2023 (several years after the accident), the City decreased the advisory speed around the curve from 35 to 30 miles per hour, added three more chevron signs around the curve, and added additional warning signs on the right shoulder near the start of the curve. 10  2. Tansavatdi’s Opposition In her opposition to the City’s motion for summary judgment, Tansavatdi argued that the intersection and the southbound approach to the intersection created a dangerous condition. She also contended there were triable issues as to whether the condition was a concealed trap, whether the City had notice of the danger, and whether the dangerous condition caused the accident. In addition, she argued that the City was not entitled to design immunity for the failure to adequately warn of the dangerous condition. Tansavatdi’s expert, Edward Ruzak, opined that the signage concerning the intersection and the approach to the intersection was inadequate. While Ruzak acknowledged that the City had installed numerous signs warning of the upcoming intersection, in Ruzak’s view this signage was not enough. For example, he opined that the City should have positioned a “radar speed feedback” sign on Hawthorne to raise “user awareness of their speed.” He opined that the City should have installed a “flashing warning beacon system to warn users of the upcoming intersection.” And he asserted that “various” additional signs should have been installed in advance of the intersection, including ones stating “BE PREPARED TO STOP” “WATCH FOR STOPPED VEHICLES,” and “PROCEED AT OWN RISK.” Finally, he opined that the City should have painted bicycle stenciling with painted chevrons in the roadway (i.e., sharrows) to indicate the presence of cyclists. Ruzak further opined that the intersection and approach was a dangerous condition and concealed trap at the time of the accident that was or should have been known to the City. Tansavatdi presented evidence of traffic collision reports and argued that the accident rate at the intersection was higher than the City claimed. 11  3. Trial Court’s Ruling In a written ruling filed September 6, 2024, the court granted summary judgment for the City. The trial court accepted “as decided that the City is immunized under section 830.6 for the design of the 2009 repaving project.” The court considered the issue left open by the Supreme Court regarding the application of design immunity to the warning signs. To do so, the trial court first found it necessary to define the “dangerous condition” at issue in Tansavatdi’s failure to warn claim. It found that the relevant “dangerous condition” was the intersection itself. It then found that the City had presented evidence to show that it considered and included warnings about the intersection as part of the approved design for the 2009 plan. Thus, the trial court found that the City had met its burden to establish that the warnings were part of the 2009 design plan and that the 2009 plan was entitled to design immunity. Accordingly, the court concluded that the City had established that it was immune from liability “for the design of the warnings in place at the time of the collision as a matter of law.” On that basis, the court granted summary judgment.6 This appeal followed. 6 The trial court made other rulings, less significant to our resolution on appeal. The trial court found that there were triable issues of material of fact as to whether the City had notice of the dangerous condition, as to whether the dangerous condition was a concealed trap, and whether the failure to warn was a substantial factor in causing the injury. In addition, the court found that the City was entitled to signage immunity under section 830.8 “for the decisions made as to what signs to post and where.” 12  E. Motion to Tax Costs On April 25, 2018, the City served a statutory offer to compromise on Tansavatdi pursuant to Code of Civil Procedure section 998 (998 offer). The City offered a waiver of costs “[i]n full settlement of this action” in exchange for dismissal of the action and a release of liability. In particular, the offer required “execution and transmittal of a General Release by [Tansavatdi], in favor of [the City]; and Each party is to bear their own costs and attorney fees and the settlement will include all existing and future medical, legal and other liens arising in any way from the subject accident.” Tansavatdi did not accept the offer. In October 2024, after the trial court’s order granting summary judgment, the City served its memorandum of costs. The City sought over $79,000, including $36,372 in expert witness fees. Tansavatdi filed a motion to strike and/or tax the City’s costs. As relevant here, she argued that the City was not entitled to expert witness fees because the 998 offer was uncertain and was made in bad faith. In a written ruling following a hearing on January 17, 2025, the court granted the motion to tax costs in part and denied it in part. As to the 998 offer, the court found that it was “not so uncertain as to render it invalid.” In particular, the court found that the inclusion of a “general release” in the offer was “insufficient to invalidate a 998 offer if the offer is limited to claims related to the instant lawsuit.” In total, the court awarded $75,979.22 in costs to the City as the prevailing party. Tansavatdi separately appealed from the order awarding costs to the City. We consolidated the appeals for the purpose of briefing, argument, and decision. 13  DISCUSSION I. Design Immunity Tansavatdi contends the trial court erred in granting the City’s motion for summary judgment. For the reasons discussed below, we hold that the City was entitled to immunity under section 830.6. We therefore affirm the grant of summary judgment. A. Legal Standards 1. Summary Judgment Where a defendant moves for summary judgment based on an affirmative defense, the defendant must show that undisputed facts support each element of the affirmative defense. (Anderson v. Metalclad Insulation Corp. (1999) 72 Cal.App.4th 284, 289.) “‘We review the trial court’s decision de novo, considering all the evidence set forth in the moving and opposing papers except that to which objections were made and sustained.’ [Citation.] We liberally construe the evidence in support of the party opposing summary judgment and resolve doubts concerning the evidence in favor of that party.” (Hartford Casualty Ins. Co. v. Swift Distribution, Inc. (2014) 59 Cal.4th 277, 286.) “The appellant, however, still ‘has the burden of showing error, even if he did not bear the burden in the trial court.’” (640 Octavia, LLC v. Pieper (2023) 93 Cal.App.5th 1181, 1189.) 2. Government Tort Claims and Immunities “Under the Government Claims Act, ‘[a] public entity is not liable for an injury’ ‘[e]xcept as otherwise provided by statute.’” (Hampton v. County of San Diego (2015) 62 Cal.4th 340, 347 (Hampton).) Section 835 provides that a public entity may be liable for injuries caused by a dangerous condition of its property under two circumstances. First, a public entity may be held liable for an act or omission by a government actor that created the 14 dangerous condition (§ 835, subd. (a)). Second, a public entity may be held liable for a failure “to protect against” a dangerous condition of which the entity had notice (id., subd. (b)). The phrase “protect against” includes “warning of a dangerous condition.” (§ 830, subd. (b); see also Tansavatdi I, supra, 14 Cal.5th at p. 653.) A dangerous condition is one that “creates a substantial … risk of injury” when the property is “used with due care in a manner in which it is reasonably foreseeable that it will be used.” (§ 830, subd. (a).) The public entity may raise an affirmative defense of immunity, even if a dangerous condition was established. At issue here is the immunity under section 830.6, i.e., “design immunity,” discussed below. (See Tansavatdi I, supra, 14 Cal.5th at pp. 653, 660.) Design immunity is often raised on a motion for summary judgment, “enabling the trial court to find the defense established as a matter of law.” (Grenier v. City of Irwindale (1997) 57 Cal.App.4th 931, 939–940 (Grenier).) B. Tansavatdi I The touchstone of our analysis is the Supreme Court’s opinion in Tansavatdi I. Tansavatdi I is not only a prior decision in this same case. It is also the Supreme Court’s most thorough and recent consideration of the doctrine of design immunity. We therefore discuss it at length. At the outset of Tansavatdi I, the Supreme Court made clear that there was one question before it—whether design immunity under section 830.6 “categorically precludes any claim that the public entity is liable for having failed to warn of a dangerous traffic condition resulting from that approved design.” (Tansavatdi I, supra, 14 Cal.5th at p. 652, italics added.) The high court ultimately answered that question in the negative. It found that this outcome was controlled by its prior opinion in Cameron v. State of California 15 (1972) 7 Cal.3d 318 (Cameron). (Tansavatdi I, supra, 14 Cal.5th at p. 648.) The Supreme Court declined the City’s request to overrule Cameron as “illogical” or poorly reasoned. (Ibid.) In explaining and reaffirming Cameron, Tansavatdi I extensively analyzed another case, Flournoy v. State of California (1969) 275 Cal.App.2d 806 (Flournoy). (Tansavatdi I, supra, 14 Cal.5th at pp. 654–655.) It did so because the “holding in Cameron is based largely on the analysis set forth” in Flournoy. (Id. at p. 654.) Flournoy was a wrongful death action resulting from a car accident on an icy bridge. The plaintiffs alleged that the bridge design caused moisture to condense on the roadway, creating a dangerous condition in freezing weather. (Flournoy, supra, 275 Cal.App.2d at p. 808.) The plaintiffs also alleged that despite notice of numerous accidents caused by ice on the bridge, the state had not posted any signs warning motorists about the danger. (Ibid.) Flournoy found that design immunity “could affect only one of two [alternative] theories of recovery.” (Flournoy, supra, 275 Cal.App.2d at p. 810.) Each theory “postulated a separate, although concurring, cause of the accident. [Citation.] The first theory asserted causation in the state’s active negligence in creating a danger, the second in the state’s passive negligence in failing to warn of it.” (Id. at p. 811.) Thus, as Tansavatdi I observed, under section 835, “‘[r]egardless of the availability of the active negligence theory, plaintiffs were entitled to go before a jury on the passive negligence theory, i.e., an accident caused by the state’s failure to warn the public against icy danger known to it but not apparent to a reasonably careful highway user.’” (Tansavatdi I, supra, 14 Cal.5th at p. 655, quoting Flournoy, supra, 275 Cal.App.2d at p. 811.) As 16 such, “‘[b]y force of its very terms the design immunity of section 830.6 is limited to a design-caused accident. [Citation.] It does not immunize from liability caused by negligence independent of design.’” (Tansavatdi I, supra, at p. 655, quoting Flournoy, supra, at p. 811.) Turning from Flournoy to Cameron, the Tansavatdi I court discussed the facts of that case. In Cameron, the plaintiff alleged that the state negligently constructed an improperly banked curve and also failed to post any warnings to drivers to reduce their speed. (Cameron, supra, 7 Cal.3d at p. 322.) The Supreme Court reversed a grant of nonsuit based on design immunity, finding that the state was not entitled to immunity because it presented no evidence that the curve’s banking was part of the approved design. (Id. at p. 326.) Additionally, the court found that even if the curve’s banking was protected by design immunity, the state could be liable for a failure to warn where there was evidence that the curve was a concealed trap and the failure to warn “is an independent, separate, concurring cause of the accident.” (Id. at p. 329.) Tansavatdi I then addressed the issue before it in light of these authorities. It rejected the City’s argument that failure to warn claims against public entities are categorically limited to situations in which the entity fails to warn of a dangerous condition not protected by design immunity. Instead, the court concluded that a claim could sometimes lie for a failure to warn of a dangerous condition created by the design of public infrastructure, even if liability for the dangerous condition itself would be barred by design immunity. (Tansavatdi I, supra, 14 Cal.5th at p. 652.) In so concluding, the Supreme Court made several points that are important for our analysis here. First, quoting its previous decision in Cornette v. Department of Transportation (2001) 26 Cal.4th 63, 69 (Cornette), 17 the Court explained the purpose of design immunity. It noted that “‘[t]he rationale for design immunity is to prevent a jury from second-guessing the decision of a public entity by reviewing the identical questions of risk that had previously been considered by the government officers who adopted or approved the plan or design.’” (Tansavatdi I, supra, 14 Cal.5th at pp. 653– 654.) Thus, Tansavatdi I emphasized that the fundamental point of design immunity is to preserve the ability of public officials to weigh questions of risk without later interference by juries, a separation-of-powers concern. Second, the reasons for not categorically extending design immunity to failure to warn claims is rooted in a distinction between “active” and “passive” negligence. (Tansavatdi I, supra, 14 Cal.5th at pp. 659–660.) That a governmental entity might be immune from suit for its “active” negligence in creating an approved infrastructure project does not necessarily immunize it from suit for the “passive” failure to warn of the danger it created, so long as the entity had notice of the danger. (Ibid.) Third, the Supreme Court cautioned that for a failure to warn claim, “the plaintiff must prove the absence of a warning was an ‘independent, separate, concurring cause of the accident.’” (Tansavatdi I, supra, 14 Cal.5th at p. 661, quoting Cameron, supra, 7 Cal.3d at p. 329.) As such, “if a plaintiff is not able to establish that the absence of a warning sign was a substantial factor in causing the injury, the claim will fail.” (Tansavatdi I, supra, 14 Cal.5th at p. 661.) Finally, as we previously noted, the Supreme Court expressly declined to address “whether design immunity might apply if the public entity is able to show that the presence or absence of warning signs was part of the approved design.” (Tansavatdi I, supra, 14 Cal.5th at p. 661.) The Court 18 noted that the plaintiffs in Cameron “specifically alleged that the state’s failure to warn was not part of any approved plan.” (Ibid.) C. The City is Entitled to Design Immunity Under Section 830.6 1. Design Immunity May Apply to Challenges to the Adequacy of the Design of Signage With Tansavatdi I in mind, we turn to the issues before us. We start with what is not in dispute. Tansavatdi agrees, as she must, that the City is entitled to design immunity for any dangerous conditions resulting from the 2009 plans. (See Tansavatdi v. City, supra, 60 Cal.App.5th at p. 441.) Tansavatdi also agrees, as she must, that the relevant “dangerous condition” is the intersection and the approach to the intersection. And she agrees that there were multiple signs warning of the intersection and the approach to the intersection that were part of the approved 2009 plans. These included a curve warning sign with a reduced speed limit advisory of 35 miles per hour, corresponding pavement markings, six chevron signs, a flashing beacon around the curve, a sign noting the steep grade of the hill, and a sign and pavement markings advising of the traffic signal ahead. Thus, there is no dispute that the City provided some warning of the relevant dangerous condition. And there is no dispute that these warnings were installed as part of an approved design (the 2009 plans). The parties disagree about the legal consequences of these facts. The City argues that design immunity bars Tansavatdi’s failure to warn claim, because the City “considered which warnings to provide” as part of an approved design. According to the City, this means that the decision to not provide additional warnings is automatically protected by design immunity. Tansavatdi argues that design immunity does not apply because, according to her, “failure to warn claims ... are not subject to design immunity” “at least 19 when they are based on a history of collisions after the roadway was constructed.” We adopt a more limited rule than urged by either of the parties. In our view, when (a) there is some warning of the relevant dangerous condition provided as part of (b) an approved design, but (c) the plaintiff claims that additional or different warnings were necessary, such claims may be barred by design immunity (assuming that all the other requirements of design immunity are met). That more limited rule is sufficient to resolve this case. We reach our conclusion for several reasons. First, “the prime requisite of … design immunity” is a “design-caused accident.” (Flournoy, supra, 275 Cal.App.2d at p. 812.) When, as here, there are warnings included in the public entity’s design, a plaintiff complains that the design should have included different or additional warnings, and alleges that the failure to have different warnings caused an accident, it is difficult to conclude that we have anything other than a “design-caused” accident. Thus, design immunity should apply. A comparison to Flournoy is instructive. As noted, in that case the Court of Appeal found that design immunity applied to claims based on the design of an ice-prone bridge, but did not apply to claims based on a failure to warn that the bridge might become icy. (Flournoy, supra, 275 Cal.App.2d at pp. 810–811.) It further reasoned that this distinction “incorporated the ‘active’ and ‘passive’ theories of negligence recognized in the common law.” (Tansavatdi I, supra, 14 Cal.5th at p. 659 [discussing Flournoy].) Flournoy’s core holding was that the design immunity created by section 830.6 “‘does not immunize from liability caused by negligence independent of design.’” (Tansavatdi I, supra, at p. 655, quoting Flournoy, supra, at p. 811.) But here we do not have negligence “independent of design.” Here, warnings were 20 provided, and they were considered as part of the roadway’s design. The only question is whether the warnings were sufficient. In this case, liability is intricately bound up with a question of design. Second, the Supreme Court has emphasized that “to establish liability for failing to warn of a dangerous traffic condition that is otherwise subject to design immunity, the plaintiff must prove the absence of a warning was an ‘independent, separate, concurring cause of the accident.’” (Tansavatdi I, supra, 14 Cal.5th at p. 661, quoting Cameron, supra, 7 Cal.3d at p. 329.) For purposes of design immunity, when a warning is provided as part of a design, it is difficult to conclude that inadequacy of that warning is an “independent” or “separate” failing different than the design itself, such that it can give rise to a separate cause of action independent of design immunity.7 Third, allowing design immunity for claims like this one helps to fulfill the core purpose of design immunity. As explained by the Supreme Court: “[T]he law’s purpose is to avoid the dangers involved in permitting reexamination and second-guessing of governmental design decisions in the context of a trial: ‘While it is proper to hold public entities liable for injuries caused by arbitrary abuses of discretionary authority in planning improvements, to permit reexamination in tort litigation of particular discretionary decisions where reasonable men may differ as to how the discretion should be exercised would create too great a danger of impolitic interference with the freedom of decision-making by those public officials in whom the function of making such decisions has been vested.’” (Hampton v. 7 To be sure, the Supreme Court emphasized the “independent, separate, concurring cause” language to make a different point (having to do with substantial factor causation). (Tansavatdi I, supra, 14 Cal.5th at p. 661.) However, the court’s focus on independent causation supports the application of design immunity here. 21 County of San Diego (2015) 62 Cal.4th 340, 349, quoting Recommendation Relating to Sovereign Immunity (Jan. 1963) Proposed Legislation, com. foll. § 830.6, 4 Cal. Law Revision Com. Rep. (1963) p. 823; see also Cornette, supra, 26 Cal.4th at p. 69 [discussing same]; Tansavatdi I, supra, 14 Cal.5th at pp. 653–654 [discussing same].) This purpose is better served by imposing design immunity in cases where the issue is the adequacy of an existing warning. True, as Flournoy, Tansavatdi I, and Cameron recognize, the separation-of-powers values design immunity protects are not imperiled by allowing juries to assess whether public entities should warn about foreseeable dangers when the public entity has failed to provide or consider a warning at all. (See Tansavatdi I, supra, 14 Cal.5th at pp. 667–668 [explaining that the rule of Cameron and Flournoy “recognizes that a design might be the best engineers can do under the circumstances but still