Why I bike to work and around in general

This started as an email to my friend Kevin, but then I realized I'd like to share it more broadly and keep it somewhere I could find it more readily.  It's the rationale and data I've accumulated about biking.  The vast majority of my commute is by bike - I live in Boston, MA and I bike year round, mostly regardless of the weather (snow, rain etc.).  I also bike for fun occasionally on the weekends, but this post deals with commuting.

Advantages

• One motivation for biking is avoiding traffic
• my public transportation option starts with the bus, so that doesn't avoid traffic
• I ride 8 miles to work instead of 5 to avoid cars
• Every time I'm on my bike in the city I'm rolling the dice for getting in a bad accident, and I need to put those odds in my favor as much as possible, so I bike along the river on the bike path instead of the streets
• I definitely still bike through the city, I just make my regular commute avoid it
• On average, the 8 mile route takes the same amount of time as the 5 mile route
• I attribute this to the fact that the 8 mile route has ~11 traffic lights, while the 5 mile route has 18
• If I push my legs very hard so they burn as bad as I can take it, and if I get very lucky and hit the lights, the 5 mile route can be faster (up to ~30%).  But that's a gamble, and a potentially dangerous one
• The bike takes the same amount of time to get from A to B, regardless of time of day etc.
• Riding "hard" gets me to work in 29-31 minutes, riding "easy" gets me there in ~35
• I've measured this repeatedly (phone GPS / Strava app)
• There is virtually no delay / time required to find parking, ever, anywhere
• The only delays that occur are the relatively rare flat tire or other repair
• If I need to be somewhere after work, I can leave after work - I don't need to leave work early to take traffic into account
• Biking combines exercise and commute time
• here's the math for me:
• biking day:
• pack bag
• bike 35 minutes to work
• shower (20 min)
• work
• bike home
• shower
• not biking:
• shower
• take public transportation to work - 45 minutes
• work
• take public transportation home
• exercise 70 minutes
• Biking reduces the commute by 10 minutes each way, but adds a shower, which to be conservative takes 20 minutes all told (changing, showering, getting dressed, doing my hair ;)  The only additional time cost is packing my bag, which is pretty fast (now).  BUT - the exercise time on the not biking day means that the biking option wins by a lot
• get to observe (and record) nature, think about problems while biking
• every spring I get to see baby ducks and geese, sometimes rabbits
• I've seen hawks eating - out on the river when it was frozen, one time in a parking lot eating a pigeon
• I've seen turtles - one massive one recently digging a hole to lay eggs, others just on the bank of the river
• I think about math / physics problems while I ride, and it forces me to develop intuition, make approximations (old-school style) since I don't have a computer, calculator, or even a pen and pencil

Disadvantages

• gear - really nice to have waterproof boots, pants, jacket*, bag*
• I don't have a waterproof jacket or bag yet, but ideally I should have, it would make things much, much nicer
• can be tough to store it during the day at work
• bike maintenance - this takes time, and really does need to be done regularly.  After riding in the rain I need brush the dirt off the bike, oil the chain.  
• cold - even with proper gear, in the winter it can get very cold - you've got the already cold ambient temperatures, and then add in the 15 mile per hour effective wind from your motion on the bike
• bringing stuff is hard - 
• I use a back pack.  Paniers (saddlebags) are also an option, but in my experience they only give you slightly more space, but then it's another thing to deal with that can break, and if they fall off during a ride (from e.g. hitting a bump) you can be in a pretty big mess
• can't easily bring a pie to work :)
• I carry my cleats tied to my backpack because they don't fit inside
• need to eat before riding home - I can get really cranky if I don't!  And / or perseverate about work

Caveats

• I'm biking in and around a city at "normal" times.  The above description / conditions break down:
• Off-peak hours:  Driving around the city off-peak hours is quite pleasant.  In grad school I worked generally from 11 AM to 8 PM, so I rarely saw traffic in the city, driving around was quite nice.
• Away from the city:  There is less traffic and distances are farther, so biking quickly become not an option or takes much, much longer than driving
• Although there are also generally not good public transportation options under these conditions
• don't get me wrong, biking in the country is fantastic and fun, however, realistically it is not as good an option compared to driving as described above for city conditions