Lyft Inc on Thursday said it will return the option for passengers to book shared rides in select U.S. markets for the first time since the pandemic, when shared trips were scrapped to halt the spread of the novel coronavirus.

Lyft said shared rides, which allow multiple passengers to split a car traveling in the same direction, would become available in Chicago, Philadelphia and Denver as of Monday. The company, which prior to the pandemic operated shared rides in 18 markets, said it plans to return the option to all those cities in the next few months.

Lyft said its mask mandate for drivers and riders remained in effect and that drivers could opt out of offering shared rides. Shared rides would also be limited to two passengers, with the middle and front seats remaining empty.

"As the country reopens, we want our most affordable ride option to be available to our riders," Lyft President John Zimmer said in a statement.

Lyft said it would pursue a phased approach to reintroducing shared rides, taking into account the mix of driver supply and rider demand and local policy on pandemic-related restrictions.

The company's decision comes as the highly contagious Delta variant of the coronavirus is raising concerns in the United States over a new wave of infections, with only around 59% of all American adults fully vaccinated as of Wednesday.

Lyft and its larger rival Uber Technologies Inc UBER.N suspended shared rides in March 2020.

Shared or pooled rides made up only a small share of pre-pandemic rides, according to U.S. city data, and have traditionally shown higher losses than private rides.

Lyft said its new shared rides product would offer more efficient booking and routing options to avoid delays and keep costs low for riders.

(Reporting by Tina Bellon in Austin, Texas Editing by Marguerita Choy) ((Tina.Bellon@thomsonreuters.com; +1 646 573 5029; Reuters Messaging: tina.bellon.thomsonreuters@reuters.net; Twitter @TinaBellon))