There is really no expectation of tips on Lyft. When I was a driver, only about 20% of my rides tipped (and I was a 4.9-4.95 driver, though it could be a race/gender thing) and it's frankly nearly impossible to track who tipped you or didn't.
Yeah. While I like what Uber is doing about tipping, even with Lyft, the system is a lot better because I don't have to decide the tip while also trying to get out and be on my way, or with someone staring at me.
I'm just lazy and don't feel like signing up for yet another service. I hate entering all those stupid details for the millionth time.