I love how much denser the suburban parts of LA are compared to other places (though I do wish it had more of a super-dense urban core), but it does take a toll infrastructure-wise. LA has a pretty extensive network of freeways, and they're still all packed. It's crazy. And impressive, in a way (I have a love-hate relationship with the 405 in particular).

On the other hand, the city I'm from originally is finally getting to widening one of the core freeways in an area that's seen a ton of growth over the past twenty years, and it sounds like just as much a pain for the people living there as the 405 construction has been in LA. There's just a far lower total of affected people since the city is so much less populated. :)