SHENZHEN - China's taxi-hailing app Didi Kuaidi began its shuttle service for commuters in Beijing and Shenzhen on Thursday, offering an alternative to existing transportation methods such as bus and subway.

The internet firm currently offers 33 bus routes in Beijing and 10 in Shenzhen, using shuttle buses from tourism agencies and car rental firms. Riders can sign up for the shuttle service on Tencent's instant messaging app WeChat and is charged on a pay-as-you-go basis.

Didi Kuaidi already dominates China's online taxi-hailing market and is competing with rival Uber and CAR Inc for ride-on-demand service, the commuting shuttle is the latest addition to its transportation offerings as the company, with more than $3.5 billion in cash reserves, seeks to make a dent in what it sees as a $16.1 billion intelligent public transportation market.

The service aims to improve the commuting experience for office workers aged between 20-40 years in the two cities, especially those whose traveling needs are not met by existing public transportation, said Li Jinfei, a manager who runs the shuttle service at Didi Kuaidi.

The shuttle routes going directly from home to work will save many the troublesome transfer between subways and buses.

For Zhang, who lives in the west end of Shenzhen but works in the city center, the service will make a real difference in how he commutes.

"The subway is too crowded and taking a taxi is too expensive," said Zhang, who signed up for a shuttle connecting his home to his workplace.

Didi Kuaidi does not own the shuttle that runs its service and instead use those that sit idle at travel agencies and car rental companies. The shuttle routes are formulated based on travel needs riders submit online.

Didi Kuaidi says it will increase shuttle routes to 100 in the two cities by the end of July based on riders' commuting needs and expand into other cities, though it didn't specify which.

The company announced last week that it has recently completed a fresh round of financing of $2 billion?from existing stakeholders such as Alibaba, Tencent, Temasek and Coatue Management, as well as several new investors like Capital International Private Equity Fund and Ping An Ventures.