Ridesharing startup Sidecar announced that California users will now be required to pay fares for rides they take using the service, moving away from a previous model where users could "donate" more or less money than was suggested. The move comes as Sidecar fights to compete against Uber, Lyft and other ridesharing services. Sidecar said the move will benefit drivers and motivate them to drive more often, improving the reliability of the service. "Our drivers rely on us as a fun, interesting way to make some extra cash with their car," Sidecar said in a statement. They've also told us loud and clear they would drive more frequently and take longer ride requests if they could reliably depend on fair payment every trip. Previously, riders had the option to pay less than what Sidecar suggested, a tactic that could be used whenever they received a ride that fell below their expectations. However, users could also abuse the system and pay $0. The only thing drivers could do in retaliation was block those users but only after they'd already given them a ride. With the change Friday, users will still be allowed to pay more if they wish, but if they don't like their ride, they'll only be able to give their driver a poor rating and leave negative feedback. The move brings Sidecar more in line with Uber, another ridesharing services that charges users a set fare for their ride. Rival ridesharing serivce, Lyft said it will still allow users to pay more or less than the suggested amount. However, the company said it has not ruled out a move to a fare model in the future. [Updated 3:12 p.m. PST Nov. 15: Lyft has backtracked on its earlier statement and said that it too will be switching to the minimum fare system in California some time in the next few weeks.] Sidecar said the change to a fare model will only affect its California riders. For now, riders in other states will still be able to pay however much they want for their rides.