Opinion ID: 2381571
Heading Depth: 1
Heading Rank: 5

Heading: setting the clearance interval a discretionary function?

Text: The trial judge found it to be clear that setting traffic signal intervals is the type of function that the discretionary function rule is designed to shield. This is so, according to the judge, because the timing of the light involves considerations of safety not only for pedestrians but for travellers, and it involves a balancing of safety needs against the need to assure adequate traffic flow, which itself involves considerations of safety as well as commerce and convenience. Balancing these facts also requires the ascertainment of facts, such as numbers of vehicles and pedestrians, and ways in which drivers and pedestrians behave in the aggregate, which are peculiarly subject to study and expertise. Subjecting the decisions of traffic engineers to litigation and to second-guessing by jurors would deter effective government. For these and other reasons, our courts have held that with respect to functions like the one here, the function is discretionary. [7] My colleagues fully agree with this analysis, but I do not believe that the record bears it out.
I think it important to note at the outset that we are not dealing here with the question whether to install a traffic signal at the intersection of Wisconsin Avenue and Fessenden Street. Cf. Urow, supra . The decision to place a signal at that location had been made many years before. The determination by the District's engineers which is challenged on this appeal concerns solely the length in seconds of the clearance interval; i.e., how much time vehicular traffic should be given to clear the intersection before pedestrians and drivers are given a green light to cross the street. According to Aguehounde, there is no support in the record for the trial judge's assertion that this narrow question required the District's engineers to balance pedestrian safety against traffic flow, commerce, or convenience, or to include in their calculus the various other considerations enumerated by the trial judge in the passage from his opinion which I have quoted. The District does not really challenge Aguehounde's reading of the record, [8] and my own search has revealed nothing to suggest that Aguehounde is mistaken. Indeed, the testimony of Aguehounde's expert witness reveals, and the District's Required Yellow Interval in Seconds chart [9] confirms, that the length of the clearance interval is set  and is supposed to be set  on the basis of a three-part formula which does not include the factors to which the judge referred. Moreover, the testimony of the District's own witnesses reflects that social, economic and political factors were probably not considered at all when the decision in question was made. In most instances, according to the District's expert, a four-second interval is selected almost automatically as suitable for any intersection. Finally, a traffic engineer who was the principal witness for the District effectively admitted in testimony which I quote in note 10, infra, that on this particular occasion, it was a faulty measurement of the intersection, rather than a high-level choice between policies, that led to what proved to be an erroneous decision as to how long the clearance interval should be. Aguehounde called two expert witnesses, Richard Pivnik, a traffic engineer, and Clyde Richard, an expert on accident reconstruction. Pivnik testified that the correct clearance interval is determined by a formula based on the perception reaction time, the accepted deceleration rate for a controlled comfortable stop, and the time it would take a car to clear the intersection. The third of these factors obviously depends on the width of the intersection. Pivnik believed that this formula  which the District applied in its Required Yellow Interval in Seconds chart  was in use in every jurisdiction... that I know of, that I'm familiar with, and that it had been an accepted formula for at least thirty years. Pivnik did not include in the calculus the other considerations enumerated by the trial judge, such as balancing of safety needs against the need to assure adequate traffic flow, and it is readily apparent from his testimony that these factors are not a part of the formula, and that they therefore play no role in this particular decision. The testimony of Clyde Richard, an accident reconstruction expert, was essentially identical to that of Mr. Pivnik with respect to the manner by which the formula is calculated. Raj Ghaman, the District's traffic engineering expert, testified that there are various tests that suggest and are commanded that clearances  signal clearances  be between three and six seconds. He stated that [al]most everybody, and I included, have used about four seconds as a magic number that works at just about every intersection. Ghaman did not contradict the testimony of Pivnik and Richard as to the factors which go into the clearance interval calculus. Moreover, his testimony indicates that, far from weighing competing policy considerations applicable at the particular intersection, District of Columbia engineers routinely set the interval at four seconds at virtually all intersections. Saraj Gyani, a traffic engineer who was the District's principal witness, testified primarily that he was unaware of any statute, regulation or policy that required a six-second interval at the Fessenden traffic light. He also expressed the opinion that four seconds was a safe interval. Gyani did not, however, contradict the evidence presented by Aguehounde as to the factors which engineers consider in setting the clearance interval. Indeed, his testimony does not suggest that the clearance interval is set at any given intersection, or was set at four seconds in this case, on the basis of a choice between policy alternatives. [10] Like most judges, I am no expert on traffic engineering. There may perhaps appear to be some intuitive merit in the trial judge's assessment of what factors engineers do or should consider in determining the duration of the clearance interval. But if the factors enumerated by the judge, or any of them, are a part of the prescribed or actual calculus, the District had ample opportunity to adduce evidence proving this to be the case. The District failed altogether to do so, however, and instead presented testimony that the interval was either arbitrarily fixed at four seconds as a matter of routine (according to Ghaman) or selected, in this case, as a result of a measuring error (according to Gyani). [11] I do not think the trial court or this court can properly come to the District's rescue in light of this failure of proof, especially given what I view as the effective destruction of the District's choice between policy alternatives theory by its own witnesses. We have recognized that where a fact is well-known by all reasonably intelligent people in the community, courts may judicially notice that fact without requiring formal proof. Poulnot v. District of Columbia, 608 A.2d 134, 141 (D.C.1992) (citation omitted). Any connection, however, between the duration of the clearance interval at Wisconsin and Fessenden and the flow of traffic, both there and at other intersections, is not sufficiently well-known or obvious to permit a court to take judicial notice of it.
Given the state of the record, the cases in this jurisdiction on which the judge relied are readily distinguishable. In each of them, the governmental decision in question was different from, and more traditionally discretionary than, the setting of the clearance interval. Moreover, as I read these cases, none of them involved a situation in which the evidence showed that no policy discretion was exercised in fact. [12] As my colleagues have pointed out, jurisdictions which have directly addressed the issue ... whether the setting of a traffic light clearance interval is a discretionary function have gone both ways. Op. at 448, n. 9. In my judgment, however, the decisions which are said to support the District's position are readily distinguishable, or unpersuasive when compared to the dissents, or both. [13] The cases rejecting the discretionary function defense, on the other hand, appear to me to constitute well-considered, albeit non-binding, precedents. [14]
It is also worth noting that two Superior Court judges ruled, at earlier stages of this litigation, that the timing of the clearance interval was ministerial rather than discretionary in nature. In denying the District's motion for summary judgment, Judge Colleen Kollar-Kotelly held: [T]he plaintiff claims that the District failed to execute [its] own policy of using a set formula by improperly measuring the width of the road. Since the District does not have immunity for ministerial acts such as measuring distances and calculations after a policy is already determined, the District cannot claim immunity [as] to this basis for negligence. Subsequently, at trial, Judge Burgess denied the District's motion for a directed verdict at the conclusion of Aguehounde's case because the figure was too small for the width of the intersection, resulting in a clearance time that was too short. Judge Burgess later reversed himself, however, and granted the District's motion for judgment n.o.v.