I use my A500 for commuting. Trip computer has the average mpg down as 37.5mpg, so it's not too bad. The mph is probably higher for most of the trip, it's the last mile or so when I hit rush-hour town traffic that kills it.
Luckily for me, there aren't any speed-bumps on my commute route. Hell, there are more speed-bumps driving to my local Tesco which is less than half a mile away than there are driving all the way to work. But if there are lots on your commute, then you might be less happy. The suspension ruddy hates speed bumps.
But, er, yeah. You should get better than 35mph out of it without too much trouble.