I commute from near the southern end of Manhattan (south of 14th St), to the northern end and beyond into the Bronx. I work at 238th St. In NYC, 20 blocks is one mile. The total distance is 13 or 14 miles, depending on the route I choose. It's a very urban commute, but I'm very lucky, because most of it is along the Hudson River Greenway, the US's most heavily used bike commuting route. I don't know how many cyclists I pass, but it's several hundred. After 125th St, there aren't as many bike commuters, and very few are going in my direction. The route is mostly flat, as it's along the river, on a part of the island that is landfill. It is also a pretty noisy route, as it is almost completely next to a highway. Headwinds in the morning can be very strong. Towards the end of the route, I hit a killer hill and then some lesser hills. The killer hill isn't long, but it's steep. The last couple of miles is in motor vehicle traffic. Most of you all would call it heavy traffic, and it is, but it's a lot lighter than it is in Midtown Manhattan, where it is insane beyond belief. Thank goodness I don't have to ride in Midtown often.
The route is terribly scenic. The Hudson River is over a mile wide. New Jersey is on the other side, with cliffs facing the river. Also along the path are some very good looking people riding their bikes and jogging, so that's another kind of pleasant scenery.
If I'm lucky, on my ride home, the wind hasn't shifted to become a headwind. It happens sometimes. Usually the direction is the same but the intensity is less, so I don't get as much of a boost going home as a challenge I have in the mornings. In the winter, the riverside is colder than the rest of the city, and boy, is it cold and windy. I'm going to try riding in heavy boots this winter.
I'm supposed to be dressed somewhat conservatively at work. Jeans are officially not allowed but are tolerated. I don't care, as I don't like jeans any more. Men aren't supposed to wear sandals, which I think is dumb, but those are the rules. Polo shirts are OK, and they are my favorite type of shirt. I usually wear my work clothes on the bike. Sometimes I'll ride in wearing shorts, and I'll change upon arrival. When I ride, I usually wear sneakers with SPD cleats on them. I don't know if they are allowed, but no one has complained.
My kids are adults, and my wife often works in the evenings, so I often have no reason to rush home.
I ride my bike to work about two days a week. The other three or so days I take the subway, which has its upsides. It is relaxed. I'm headed against traffic, so it's not terribly crowded. I get to read. The subway ride takes the same amount of time as the bike ride, so my decision of which mode to use isn't based on time. I also get to look at all the different people, which I enjoy. New York is a great city for people watching. I think I might see a thousand faces in a day. Stop and think about that. How many faces do you see in a day?