The limo/chauffeur/driver has a valid license to operate a limo service, not a cab service. They are operating as a cab service when dispatched by UberCab, and so if they do not have a cab license, it would seem that they are operating outside the law.
The cars that UberCab dispatches are in appearance and in license compliant with black car services and are hired on-demand on a prearrangement basis through a phone application. In addition, a customer must register for the service and provide a credit card to use the service.
This are not random people calling a cab station, this are specific customers arranging for private transportation they could do by phone, but do so using an application instead.
Because, per San Francisco city bylaws, cab services, and only cab services, can pick up people immediately. Limo Services must arrange pick-ups at least one hour in advance.
Yes, you have to sign up for the service first and get the phone app, but I don't see that this makes a difference. What's pre-arranged there is the ability to use the service. When I turn on my TV, go to the "On Demand" section, pick a movie, and watch it, I doubt anyone would say I'm watching a pre-arranged movie, even though I had to previously subscribe to the cable service in order to do so. Seems to me that's essentially the same as what UberCab is doing.
Let's use your example. On demand would be you stopping a taxi by waving like a madman on the street. That's immediate. UberCab is like me calling a Limo service (which is my example above) asking for a limo to pick me up at the airport and the limo arriving in 10 minutes. Hell I once called from the airport and a flight a different customer was in was delayed by 3 hours, so they gave me his limo sedan. I literally had on demand service, since I didn't have to wait for the limo to get there. I've done this in multiple states and it has never been a problem.
Let's say I arrived at the airport and forgot to book my limo. You're telling me that I can't call a limo service and ask for one? And that if I do I have to wait an hour? That's not how it works nor how its stated by the law.
Second, I think I was remembering this quote
> Limos in U.S. cities usually have to prebook an hour in advance, by law, while only licensed taxis can pick someone up right away
which may not apply to SF. Do you have a source that there is in fact no such time-limit in SF?
I've seen (and taken advantage of) black limos cruising the streets of San Francisco at busy times (New Year's Eve, closing time), picking up passengers taxi-style. It's presumably illegal, but the police generally have better things to do at these times than harass limo drivers.
I find it interesting because there is a record of SF not allowing limo services to top for customers, but I can't find any on the one hour restriction. Honestly I think that comment was taken out of context regarding the companies themselves having a one previous hour arrangement policy.