Even before this rollup there was a big difference, with US departments tending to buy heavily customized models and European departments buying a standardized model.
US spending involving federal grants that are spent by municipalities probably doesn't help (it's easy to spend someone else's money).
One major difference with European appliances is that they are all based on off-the-shelf commercial truck cab chassis. It saves a lot of money when you can just go buy a crew cab Scania or Volvo and then fit your own body to the chassis.
They bodywork is still pretty heavily customised per agency, but this mostly comes down to simple sheet metal work, ie places to store various gear in the lockers. The manufacturers have a significant library of designs they can easily adapt to any need.
Larger fire trucks also contribute to poor urban planning. Perhaps there is a solution in fire departments having to import cheaper equipment from Europe. This might be a useful forcing function.
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