Car rental service companies are expanding their fleets and are seeing a growth in their revenue despite the growth of ride-hailing and car sharing services. Industry watchers warn that the industry could see its market share shrink should the car rental services not continue to innovate. Industry officials and observers say rental cars remain a popular option for those who need to travel longer distances, companies sending employees on the road and insurers who need to provide a replace rental. Avis Budget Group reported in its 2015 fourth-quarter earnings call that in cities where ride-hailing services are most popular- Chicago, Boston, San Francisco, New York and Washington, D.C. - rental day volumes increased 2%. And at Enterprise Holdings, they reported in October that its airport car rental revenue in the U.S. raised 10% compared to the prior fiscal year. Yet rental car companies are not standing still, Avis purchased the car-sharing service Zipcar in 2013 and has said that it expects to grow to more than 1 million members this year. Hertz notes that its Gold Plus Rewards members can skip the wait at the counter and go right to their car. Renters can see information about their vehicle on the rental company's app. However, the popularity of ride-hailing service with business travelers is on the rise and the use of rental cars is falling. Uber and Lyft reported in their first quarter the number of trips taken by corporate trekkers nearly doubled the same period last year.