20mph on a residential street is perfectly reasonable. Urban roads on the other hand are usually more like 30-35mph where I live, which is also perfectly fine.
I guess this is using American convention where people are expected to go 1.2x or 1.3x the speed limit. Although funnily residential roads I know doesn't need speed limit for this, solely because of road quality.
No, it's in Europe and you're not "expected" to go over the limit at all.
If you want to step on it, leave the city. Most non-access roads in non-built-up areas are 50mph, and more for motorways. Some major urban thoroughfares are also 45mph.