car or no car?

Let's look at the trips that I've taken this year.  Through the end of September I have used my car ~60 days, of which I really *needed* to drive ~20.

Days where a car was legitimately useful: ~20
5 days during ski season for night skiing after work
3 days during ski season for going skiing on non-work days
9 days due to friends in town
3 trip to some place in the boonies
1 trip for buying large items

Days of low value car trips: ~35
20 days for the sake of moving the car or fixing the car (no car, no need to do this)
5 days due to being nice and volunteering to drive (no car, can't)
3 days due to long work days (bus, or just leave!)
2 days due to picking up friends from the airpor (light rail)
1 days due to laziness
1 day due to being sick
1 day due to other reasons1 days to pick up free stuff

Now let's look at how much these trips cost me.  Looking at my costs so far this year, I project owning a car costs me about $1600/year
$120/year registration fees
$360/year insurance
~$160/year in tolls for gratuitously moving my car to/from work
~$130/year in parking tickets (for when I forget to move the car...  still cheaper than $1200/year for a spot in my building's garage)
~$300/year in maintenance
~$500/year in gas

By owning my own car, I have some flexibility to use my car whenever I want (assuming my car is in the right place), but I also need to do a large number of trips just for the sake of keeping my car functioning and avoiding parking tickets.  Owning a car costs me about $1600 a year.  Using a Zip car would cost me about the same amount of money.

Since costs are comparable, it comes down to ease.

Doing the Zip car would mean I would need to reserve a car in advance. I wonder how that would work for ski trips. It would probably be a bit more annoying when skiing, but not too much worse considering how nowadays I need to make sure my car isn't in the garage at work.  Perhaps it might even be easier!

On the flip side, I'll make less unnecessary trips, which means less time in traffic and more reading/sleeping.  It also means I don't have to worry about doing maintenance on my car, which would free up a few days on my weekends each year.  I think this balances out the days where I could have used to car for an easier commute for those long days in the office.

Overall, it's a wash.