Executive Summary: Key Legal and Evidentiary Issues

• Whether the proposed modification of the certified class improperly added residents of Chemin de la Butte-aux-Renards (CBR) whose alleged nuisances did not flow from the impugned truck-route by-law but from longstanding heavy traffic.
• Extent to which the 2018 municipal by-law (Règlement 547-5-1) actually changed truck traffic patterns on the CBR, given earlier regulations that already allowed heavy trucking along that road.
• Adequacy of class representation where the current representative wished to withdraw and proposed a replacement (Mr. Duff) who lived on the CBR and would not fall within the existing certified class.
• Impact of the requested amendment on proportionality and judicial economy, including expected extra expert evidence, pleadings amendments, interrogatories, and further delay in a file already pending for over seven years.
• Relevance of prior litigation (the Benoit injunction case) and whether res judicata barred the new claims by CBR residents or limited their ability to participate in the class action.
• Question of prescription (limitation) for the proposed new members’ claims, given allegations of continuous neighbourhood disturbances rather than discrete, easily dated acts.

Facts and procedural background

The dispute arises from heavy truck traffic in the City of Varennes, Quebec, and its impact on nearby residents. In October 2017, the City adopted Règlement 547-5-1, amending its existing truck and heavy-vehicle circulation by-law (Règlement 547) and modifying the list of roads where heavy trucks were prohibited, as well as the official truck circulation plan. The new by-law came into force on 16 July 2018. Residents alleged that this regulatory change drastically altered the heavy truck route so that trucks now had to use Route Marie-Victorin, Montée de la Baronnie and Chemin de la Baronnie to access the industrial zone and the new industrial-port zone in Varennes, causing excessive noise, vibrations, dust, pollution and loss of enjoyment of their properties. On 15 January 2019, resident Marie-Ève Dulude filed a motion for authorization to institute a class action and to be appointed representative plaintiff. The proposed class consisted of individuals and agricultural operators living on defined segments of Route Marie-Victorin, Montée de la Baronnie, Chemin de la Baronnie, and nearby transversal roads, all allegedly suffering abnormal neighbourhood disturbances because of the new truck route. In March 2020, the Superior Court authorized the class action. Dulude then filed and amended the originating application in the certified class action. In January 2022, another resident, Jessy Riendeau, replaced Dulude as representative plaintiff. In October 2022, the Court approved a modification of the group description, refining the geographical definition of the class but still centered on the roads directly affected by the rerouted heavy truck traffic.

Nature of the proposed modification

In February 2025, Riendeau filed a motion seeking two main orders: first, permission to modify the class description to add residents and agricultural operators along Chemin de la Butte-aux-Renards (CBR); and second, approval for Mr. Richard Duff, a CBR resident, to substitute for her as representative plaintiff. The proposed new members were approximately 50 individuals and agricultural owners on the CBR, described broadly as all persons (owners, tenants, occupants, and agricultural operators) who had resided or operated there since 16 July 2018. Riendeau argued that these CBR residents suffered the same type of abnormal neighbourhood disturbances as existing class members: noise, dust, vibrations, diesel odours, and loss of enjoyment of property caused by heavy truck traffic. She further asserted that the 2018 by-law had the effect of no longer prohibiting heavy trucks along the entirety of the CBR, thereby worsening the situation for those residents. On the substitution issue, Riendeau told the Court she no longer had the motivation or personal capacity to continue as representative, citing changes in her personal life and professional activities, and proposed that Duff replace her, emphasizing his prior advocacy and experience as mandatary in earlier litigation brought by CBR residents.

Arguments of the parties

The representative plaintiff maintained that adding CBR residents would not change the nature of the class action. In her view, the factual matrix remained one of nuisance and loss of enjoyment arising from the City’s truck-route regulation, and the common issues already authorized—such as whether the City incurred no-fault liability and civil liability by adopting Règlement 547-5-1, and whether members were entitled to injunctive and monetary relief—would still apply. She also contended that Duff was well placed to represent the class because he lived on the CBR, had long engaged with the City about truck traffic, and had served as mandatary for 24 residents in a 2017 injunction and damages action against the City and trucking-related companies. The City opposed both the amendment and the substitution. It argued that the complaints of CBR residents were materially different from those of the existing class: the CBR had allowed heavy truck traffic since 2001, well before the impugned 2018 by-law, so those residents’ problems did not arise from the regulatory change at the heart of the certified class action. The City also pointed out that 24 CBR residents (including Duff) had already brought, and lost, an injunction and damages action (the Benoit case) regarding heavy truck traffic on part of the CBR, and that adding them would unnecessarily complicate and lengthen the proceedings. The City further submitted that Duff, as a CBR resident, had no sufficient interest to represent a class defined around different streets and impacts caused specifically by Règlement 547-5-1.

Court’s analysis on the class amendment

The Court framed the issue within Quebec’s Code of Civil Procedure, particularly articles 585 and 588 (judicial control over amendments in class actions and power to modify or split the group) and article 206 (general rules on amending pleadings). These provisions require that amendments not be contrary to the interests of justice, not cause undue delay, and not amount to a wholly new, unrelated claim. The judge emphasized that the “frame of reference” for any amendment is the original authorization judgment: in this case, the core of the class action is the alleged impact of Règlement 547-5-1 and the new truck route on residents along specific roads. The Court examined the regulatory history and evidence about the CBR. In 2001, the City had adopted Règlement 547-2, which expressly allowed “free circulation of trucks and tool vehicles in all directions” on the CBR, and subsequent amendments confirmed that the CBR was not included among roads where heavy trucks were prohibited. The prior Benoit injunction litigation, which dealt with a 1.6-kilometre portion of the CBR bordered by about 15 residences, also showed that the road had long been exposed to heavy truck traffic and noise, irrespective of the 2018 by-law. The Court noted that neither Riendeau’s amendment motion nor the supporting sworn statements alleged that the new 2018 truck route had affected the CBR; Duff’s own affidavit described a longstanding, gradually increasing flow of trucks and efforts since around 2000 to seek a bypass. On that basis, the Court concluded that the CBR residents’ alleged harms pre-dated the 2018 by-law and did not stem from it. While the type of nuisance (noise, dust, vibrations) resembled the class members’ complaints, the legal link—causation by Règlement 547-5-1—was missing. Adding these residents would therefore graft an “entirely new” claim onto the class action, based on a different factual and legal cause (historical truck traffic rather than a specific regulatory change) and outside the authorized common issues. Moreover, the proposed description was drafted so broadly—covering everyone living or operating along the entire CBR since July 2018—that it would include people, like Duff, who had already been affected by truck traffic before that date. The Court found this overbreadth inconsistent with the principle of proportionality and the need to tailor class definitions to the underlying cause and common questions.

Court’s analysis on delay, res judicata and prescription

The judge also held that, even apart from the “new claim” problem, the timing and procedural impact of the amendment weighed strongly against granting it. The case had been underway since January 2019 and had already seen multiple debates, including a previous modification to the group description in 2022. No satisfactory explanation was offered for why the CBR residents were only sought to be added in 2025, despite their long-standing complaints and earlier litigation. Allowing the amendment would almost certainly require a new case protocol, further amendments to the originating application to insert facts related to Duff and the CBR, fresh precision or striking motions, new examinations (including of Duff and City representatives), follow-up on undertakings, and possibly additional or revised expert reports. The Court considered that these steps would add months to an already mature action and be contrary to the interests of current class members who had been waiting years for their case to reach trial readiness. On res judicata, the City argued that the Benoit injunction judgment, which dismissed claims by Duff and other CBR residents against the City, barred the CBR residents from advancing similar claims in the class action. The Court rejected this, finding that the strict triple identity required for res judicata—same parties, same object, same cause—was not satisfied. While Duff and the City appeared in both proceedings, the 24 mandants in Benoit were not equivalent to the class; the injunction conclusions only partially overlapped; and, crucially, the legal cause in Benoit (increased truck traffic due to industrial operations along the CBR and an alleged failure to build a bypass) was distinct from the class action’s cause (harm flowing from Règlement 547-5-1 and the new truck route). Regarding prescription, the Court noted the City’s argument that the CBR residents’ claims were time-barred but declined to rule definitively at this stage. Given the allegations of continuous neighbourhood disturbances, the judge held that prescription was not clearly apparent on the face of the record and should, if necessary, be decided by the trial judge after hearing full evidence. Thus, prescription was not a reason, in itself, to deny the amendment.

Decision on substitution of the representative and overall outcome

Once the Court refused to add CBR residents to the class, it followed that Duff, a CBR resident, could not be substituted as representative. Because he would not qualify as a member of the certified class, he lacked the “sufficient interest” required by the Code of Civil Procedure and could not ensure adequate representation of existing class members. The Court took note of Riendeau’s sworn statement that the litigation had been personally burdensome and that her circumstances had changed, affecting her ability and motivation to continue. It stressed that a representative in a class action must actively and competently defend the group’s interests, though perfection is not demanded, and flagged that another member of the existing class might still be appointed as a replacement representative in the future. In the result, the Superior Court of Quebec dismissed the representative plaintiff’s motion to modify the class description and to substitute the representative. This meant that the class remains limited to residents and agricultural operators along the specified portions of Chemin de la Baronnie, Montée de la Baronnie, Route Marie-Victorin, Chemin de la Côte-Bissonnette and nearby transversal roads, all allegedly affected by the 2018 truck-route by-law. The successful party in this decision is the City of Varennes, which successfully opposed both the proposed expansion of the class to include CBR residents and the proposed substitution of Mr. Duff. However, the Court did not award or quantify any damages, costs or other monetary relief in favour of the City or anyone else in this judgment; it simply ordered that “costs are to follow,” so the total amount ordered in favour of the successful party cannot be determined from this decision.