For my trip to Portland for the XOXO event, I opted to go by train and use car2go here in Seattle and down in Portland. The train was $100 with tax round-trip including business class each way. The train has Wi-Fi, which is halfway reliable in the more populated areas of the route. (Business class on the 3 1/2-hour route gets you a nicer seat, including a single when you're traveling alone, and a power outlet, as well as a $2 discount on the club car, which has fairly decent food.)
car2go is a one-way car-sharing service, unlike ZipCar, which requires that you return the car to its allotted parking space at the point of origin. car2go has negotiated with cities to pay them in lieu of lost parking fees. The car has to be returned within the home zone, which can be as large as an entire city or metro area, but not to any particular place within it.
Depending on the city, you can park nearly anywhere there is no time-of-day "no parking" restriction. In Portland, everywhere; in Seattle, it has to be a two-hour or longer or unrestricted spot. You don't feed a meter, either; that's included. The cost in Seattle and Portland is 38¢ per minute up to a cap of $14 per hour or $72 a day. Seattle adds 20% tax! Portland adds none.
While it's only 180 miles to Portland, and it should take about three hours, my trips invariably take four or longer. There's always an accident or slowdown. I need to stop and stretch my legs. The commuter train is about 3 1/2 hours; it's a bit longer for the long-haul Amtrak runs that span the whole Pacific coast.
Not only do I have to deal with the tedium of being at the wheel, it carries a cost beyond gas. The IRS currently allows 60¢ per mile reimbursement. For the 360-mile roundtrip plus probably 50 miles of driving within Portland, I would have paid or incurred a total of $260 in gas and wear and tear.
I checked on rental cars to combine train and a local car: $250 was the best I found for renting a car anywhere near the train station. Plus, I would have had to pay the high cost of parking in downtown Portland, which rivals Seattle. Parking is tight, thus the cost.
I stayed with my brother-in-law and his wife, and their neighborhood always seemed to have a few cars within a half-mile to one mile away. It was good to need to walk, too. A few nights, I'd return late and park in front of their house, and the car would be there in the morning to carry me off.
Between using a car2go from home to the Seattle train station and back on my return (several were within two blocks of the station), and a couple dozen short-distance uses in Portland, the grand total was about $104: no feeding meters, no worrying about finding a long-term spot, and several miles of good walking, too. I think it was the right call.
(car2go ain't perfect. A car ostensibly within a few blocks of my house wasn't present, and I had to dash to get to a cluster a half-mile further away, which disappeared from the app display after I found the missing car was — missing. I couldn't sort out the weird trunk opening mechanism in a rush, and had to call to get the firm to deal with it when I parked near the train station. [I had made sure everything was closed, and the car insisted it wasn't.] They took care of it. But I made the train and everything after that was smooth sailing.)