- hard tires that lower rolling resistance but increase noise. this combined with thin sidewall tires.
- lax enforcement of the noise ordinance with respect to riced out civic coffee can exhaust. these are rarer in 2018 as its impossible to install one without the emission control balking at you.
- streets that havent been paved since the carter administration
- heavy trucks with massive turbochargers and oversized "ram" air intakes (vortec, etc..) to appeal to businesses that want to save fuel costs. Vortec type intakes especially are deafeningly loud at scale.
- trucking companies that dont size their loads. Do not send a 53' lowboy into a densely populated city street. there are quieter options. sub it out to a millwright or last miler.
- heavy construction equipment companies that insist if they add catalytic converters, mufflers, or noise controls theyll have to declare bankruptcy. Same goes for companies that include the absolute loudest "motion" alarm for equipment (the beep beep sound.) Im looking at you, Komatsu.
- Cities that tolerate lax air standards for older construction equipment. these translate into lax noise standards as well.
- garbage trucks. Heil brand trucks are absolutely the noisiest trucks on the planet because they dont include ameneties like bumpers for their skids, or bumpers for the top of the truck to cushion the bin when it hits the rooftop. The arm for loading plastic bins was designed by a grad student and it shows. High speed lift and slam.