NEPA Pavement Over Tree Roots. The court held that Caltrans did not adequately analyze whether additional paving would damage old-growth redwood trees by limiting their roots’ oxygen intake. The EA stated that the type of paving to be used for the project would allow for greater oxygen diffusion to the soil than traditional material. The court explained that the EA should have addressed whether the special paving material would avoid adversely impacting trees. “Utilizing this ‘thinner’ form of cement does not mean that roots will have sufficient access to oxygen. . . . Token generalities that the cement will ‘allow for greater oxygen diffusion’ or ‘provide greater porosity’ or ‘promote air circulation’ beg the question whether enough oxygen will still seep through.” The court concluded that the effects of paving were highly controversial because there was a substantial dispute as to the impacts on trees, and therefore an EIS should be prepared. Construction in Trees’ Structural Root Zones. The court held that Caltrans did not adequately analyze the impacts of construction in the structural root zones of protected old-growth redwood trees. A California State Parks guidance document stated that “there should be no construction activities in the structural root zone of a protected tree” because the work could injure tree roots and introduce root disease. The court held that Caltrans should have explained why, in light of those risks, construction in the trees’ structural root zones would not introduce root disease or otherwise adversely impact the trees. “Caltrans is a separate agency and is not bound by the [State Parks] Handbook. The point here, however, is that Caltrans never provided any explanation as to why these guidelines are being ignored.” The court concluded that these effects were highly controversial because there was a substantial dispute as to the effects of construction on trees, and therefore an EIS should be prepared. Impacts of Noise on Park Visitors. The court held that Caltrans did not sufficiently study the noise impacts that would result from additional truck traffic. The 2010 EA stated that the project would not appreciably increase traffic noise levels because the number of trucks using the highway would not increase. Caltrans relied on a study of the project’s economic impacts, which contained two paragraphs discussing traffic impacts in broad generalities, and was based on the online survey responses of 14 non-representative local businesses. The court ruled that this study was inadequate to support Caltrans’ conclusion. The court also reasoned that the bigger tractor units of the extra-long trucks would likely be louder than trucks that could use the existing highway. In addition, the court held that the project could still have a significant noise impact for NEPA purposes even if Caltrans concluded that the project would not result in traffic noise impacts pursuant to FHWA’s noise regulations under the Federal-Aid Highway Act (23 U.S.C. § 109(i) and 23 C.F.R. Part 772). The court concluded that an EIS was required because the impacts on park visitors was highly uncertain, and the uncertainty could be resolved by further collection of data and analysis. Risks of Truck Collisions with Trees. The court held that Caltrans should have considered the potential increased damage to old-growth redwood trees along the highway from head-on collisions with extra-long trucks. The court explained that even if there would be no greater risk of collisions, the heavier and larger tractors of extra-long trucks could cause more damage to trees than trucks that could use the existing highway. Risks to Leaning Trees. The court rejected the plaintiffs’ argument that Caltrans should have considered the potential for the project to cause leaning trees to topple. The court noted that the issue of tree lean was not addressed in any of the supporting environmental documents and was not raised during the public comment period—it was raised for the first time by the plaintiffs during litigation. Furthermore, there was no evidence in the record to indicate that the trees were leaning at a dangerous angle. The court held that there was insufficient evidence to indicate that the issue was relevant and should have been considered.