The chain requirements impact all drivers traveling on I-80 during winter storms, particularly those crossing Donner Pass. Failure to comply with these regulations can result in being turned back at checkpoints or facing dangerous driving conditions. R1 and R2 levels allow some exceptions for vehicles with snow-tread tires or four-wheel drive, but R3 conditions require chains on all vehicles. Risks include accidents, road closures, and stranding due to rapid weather changes. Heavy-duty trucks and vehicles towing trailers are especially affected, as they are often required to chain up regardless of conditions.