Shared carpooling (called "slugging" here) has a been a viable commuting option for people in the DC area for decades. No money changes hands; the point is that a car with 3+ people can use the much faster HOV lanes.
This might be a small detail that matters big if you start driving for Lyft. What does your personal auto insurance policy cover if a paying passenger gets hurt in an accident in your car?
It is also only active during a Lyft ride.
Even many doctors don't have malpractice insurance above $1 million (depending on speciality and state) -- most policies are $100K-$300K/claim, $1MM-$3MM/all claims (http://jop.ascopubs.org/content/3/5/274.full). So Lyft is providing more liability insurance than many doctors carry.
If you're demanding absolute 0% risk for the Lyft driver financially, this would not cut it, but very little anywhere is absolutely no risk.
If a tree falls in the woods...
Slug line (two words) is apparently a screenwriting term--which I didn't know.
http://farm9.static.flickr.com/8098/8585051792_3f22025467_m....
I used to work in Crystal City, and on my commute home I would see dozens of people -- probably more than 30 most days -- lined up at the designated slug line stop.
Given that, I doubt Lyft (marketed towards urban millennials who have smartphones and are cool with riding around in cars with mustaches) and Slugging (mostly used by staid, middle-aged, middle-income workers) are going to compete with each other.
(Still kicking myself for not finishing that app for Slugline-like ridesharing 6 or so years ago :) )
For instance, 2,425 parking spaces just for people slugging into the city[1].
395 and 66 are two interstates that connect DC to the Virginia suburbs. The HOV lanes on 395 are usually more open and faster than the main highway. 66 is entirely HOV inside the Beltway during rush hour, so if you want to go that way at all, you need passengers.
Virginia just added HOT (passengers or pay) lanes on the Beltway itself; these are usually very clear because you need a transponder to even travel within them legally, and most people haven't bothered to get one. Maybe because the Beltway doesn't actually go into the city, so the utility is low for rush hour.
The benefit of HOV on 395 & 66 comes from having limited access. The lanes get crowded during rush hour, but they still move faster because of less merging & exiting. When traffic is all moving in the same direction at the same speed it flows smoother.
The changes to the Springfield interchange did a lot to prevent backups by reducing the amount of lane changing necessary to get on and off the Beltway.
There are many reasons for these kind of underground economies to exist, but one of the most striking ones to me is race. Try asking a black friend in DC whether they get picked up by cabs as easily as their white counterparts. Then there's both the drivers and riders, who have so little cash they can't afford the extras imposed by a traditional transportation company. That's when there's even a form of transportation at all; VANS exist solely to fill the empty void left by the largely nonexistent public transit of Brazilian favelas.
Other concerns (seriously, you should read the first article) include price and time: "Hale has practical reasons for putting his own safety at risk. "Cabs are too high nowadays," he says. "Most of the time, if you're not going too far, a hack is only $5. With cabs it's a $10 trip to go nowhere." As for public transportation: "If I'm going to take the bus to work, I leave at noon. If I catch a hack, I leave at 1:30."
[1] http://www2.citypaper.com/story.asp?id=6264 [2] http://www2.citypaper.com/film/story.asp?id=15396 [3] https://web.archive.org/web/20100108192651/http://www.gsd.ha...