It works for parents here in NYC. Traffic mostly moves slowly. Nowadays, a lot of cyclists are taking the lane, so to speak, and motor traffic waits behind until it can change lanes and pass.

Some parents in my neighborhood have old banana seats installed on their bikes, attached to the seatpost and the rear axle. They can hold kids as big as around 10 years old. The trip to school is rarely long, and then off to work. It's a fairly common sight. In fact, some people have things like the Yuba Mundo cargo bike, and some ride bakfietsen.

Yuba Mundo:



Bakfiets (meaning box bike, and the plural is bakfietsen):

So it's really not necessary to be nimble and quick on a bicycle commute... which is exactly what I thought. It's not necessary here either on a bicycle commute.

Right. Those who think it's necessary may be spending a lot of energy dodging cars and getting out of their ways. If we just use the road the way everyone else does, then we ARE traffic, we ARE the way, not in someone else's way.

That's generally the attitude I take. I can't do that with my daughter though. People are insane. They get worse when they're in cars.

Of course, you have to decide with your own judgment of your own circumstances. I'm not saying anyone can do it anywhere. I lived in New Jersey for 26 years, and there's some pretty bad driving there.

Hills?
If you can't pump it, hump it.

One thing that has not been touched on is that one cannot merely ride more hills, or even more miles to improve performance. If you're constantly riding too high a gear (running a cadence down in the 60's to 70's) or your bike is not set up well for your body dimensions there will be a definite limit on how much you can change performance. Also, when tackling a climb that ends more steeply it's important to not attack the first part of the climb. You can't get a head start on a long hill.

Note: I will agree that pushing higher gears can have a role in getting better on hills, but I don't think that works very well if one is not in shape in the first place.

I've been lifting weights lately, including doing squats. Hills are getting much easier for me. I have one very steep climb on my morning commute, and I normally use my small chainring. Yesterday, I used my middle ring. It felt very different to skoot up the climb, which feels like a staircase, without using a low gear. I weigh 153 pounds, and I'm squatting with 80 pounds on my shoulders.