Where do you guys have 55 mph where it's not appropriate? A LLM is telling me that 55 mph is your random urban interstate. The equivalent where I live is 80 km/h on motorways inside city/town limits, which is 50 mph, and it feels very appropriate, cars make a ton of noise and you don't want the full motorway speed in the city. And that's basically the fastest you'll ever go in a city, when it's an actual motorway (often elevated, ramps, sound barriers). Other roads (even big and important) are ~43 mph and the general urban speed limit is ~31 mph.