Maybe you’ve been there before: An hour after you get out of your Uber, you realize you dropped your keys or left your sunglasses behind in the car.

It will now cost you $15 to get those items back.

The new lost-item fee was introduced by Uber Technologies Tuesday in Boston and Chicago, and it will expand to all US cities by September.

The change is one of several Uber is launching in response to complaints from drivers that the company doesn’t do enough to support them. The fee will be paid to drivers, not the company, and riders will also have the option to add a tip.

According to Tom Maguire, Uber’s Boston general manager, the average driver returns 11 lost items a year. But until now, there was no way to compensate them through the app, with drivers generally relying on riders to tip in cash.

“That’s a lot of lost time and lost money,’’ Maguire said.

Riders will be charged only if they agree to have the lost item returned.

By contrast, taxi drivers in Boston turn over lost items to the police, and passengers are also directed to contact the police, not the cabbie. Police then contact passengers when the lost items turn up.

Other changes Uber announced Tuesday include a 24-hour, seven-day-a-week support hotline for drivers, which also launched in Boston and 15 other cities and will eventually expand across the country.

And drivers nationwide will no longer be penalized if a passenger gives a poor review of a ride that is not related specifically to the driver’s performance, such as a technical issues with the app.

The moves build off Uber’s June announcement that it would install a tipping feature in its app, ending years of resistance to a top demand from drivers. Long available for drivers with Uber’s rival Lyft, in-app Uber tipping launched in Boston earlier this month.

Uber has faced a series of scandals this year, culminating in the forced resignation of former chief executive Travis Kalanick. The trouble at Uber included questions about how the company treats its drivers, after Kalanick was caught on video berating a driver who complained about pay rates.

►Lyft rises on Uber’s missteps, B10.

Adam Vaccaro can be reached at adam.vaccaro@globe.com. Follow him on Twitter at @adamtvaccaro.