According to the Transportation Sustainability Research Center’s (TSRC) 2014 CarSharing Outlook, as of Jan. 1, there were 24 active shared-use vehicle systems in the U.S. serving about 1.2 million car-sharing members using 17,179 vehicles.

While small compared to the overall car rental market, between January 2013 and January 2014, car-sharing membership grew 38% in the U.S. while fleets grew 42%, according to the study.

The three largest car-share operators in the U.S. — Zipcar, Enterprise CarShare and car2go — comprised 87.2% of the market in January, while car-sharing programs run by rental companies represented 72% of the car-sharing memberships, according to the study.

Here is an update on the market by company and an announcement of a tech initiative from Verizon.

Zipcar

Acquired by Avis Budget Group in 2013, Zipcar has grown to nearly 30 major markets in the U.S., Canada, the U.K., Spain and Austria, including 30 airports.

This year, Zipcar launched ONE>WAY in select markets, a service that allows users to make one-way or “point-to-point” trips within a specified geographic boundary.

In October, Zipcar announced two new partnerships: to become a car-sharing provider for the General Services Administration (GSA) and to provide memberships to nearly 45,000 Southwest Airlines and AirTran Airways employees in all Zipcar cities.

Enterprise CarShare

Enterprise Holdings has grown its car-sharing initiative, Enterprise CarShare, through the purchase and consolidation of independent networks. Similar to Zipcar, Enterprise CarShare extends its pay-by-the-hour services to individuals and across multiple industries: universities, businesses and government.

The service is available on more than 75 university campuses, 40 U.S. government and business campuses and in nearly 20 major U.S. markets.

This year, Enterprise CarShare has acquired two well-established independent car-sharing brands — Toronto’s AutoShare CarSharing Network and Denver-based OccasionalCar.

In the government sector, Enterprise CarShare was also recently named one of the General Services Administration (GSA)’s car-sharing providers for its one-year pilot car-sharing program.

Enterprise also runs Zimride, an online ride-matching program, and Enterprise Rideshare, a carpooling and vanpooling program for commuters.

Hertz 24/7

In 2013, Hertz rebranded its car-sharing initiative from Hertz On Demand to Hertz 24/7. Last year, the service launched globally and is currently available in several countries, including Australia, Belgium, Canada, Germany, the U.K. and Italy.

Nationally, Hertz 24/7 is available in various cities as well as at college universities.

Hertz has not announced any expansion in 2014. However, by 2016, “the company will be prepared to have approximately 500,000 Hertz 24/7-enabled vehicles in service globally,” the company said in a statement last June.

car2go

Daimler’s car2go, specializing in one-way, point-to-point rentals of smart fortwo vehicles, was operating in eight countries and 27 cities worldwide, as of July 2014.

Nationally, car2go has expanded to several cities this year, including Los Angeles’ South Bay region, Brooklyn, N.Y., and St. Paul, Minn.

In September, car2go acquired RideScout LLC — a ride-sharing system similar to Uber — that allows users to search and compare ground transportation options in 69 U.S. cities.

DriveNow

DriveNow’s car-sharing service is a joint venture between BMW and Sixt Rent a Car. Available in Germany, Austria and San Francisco, DriveNow offers all-electric BMW 1-Series compacts and MINI models.

In San Francisco, DriveNow expanded its electric BMW ActiveE fleet by 80 vehicles to a total fleet of 150 ActiveE vehicles.

Verizon Launches Car-Sharing App

In September, Verizon Enterprise Solutions announced that its Verizon Auto Share car-sharing mobile app will be available by the end of 2014.

Verizon Auto Share is designed to enable rental companies to provide their customers with an enhanced rental experience without interacting with an on-site attendant, says the company.

Using the mobile app on smartphones or tablets, renters can scan a QR-code on the vehicle’s windshield, producing a key fob on the mobile app that allows the driver to unlock and start the vehicle, says the company.

“With urban populations projected to represent 7 out of 10 people by 2050, industry experts note that car usership and peer-to-peer sharing via a mobile application is increasingly replacing car ownership as a core part of the connected lifestyle — particularly among young people,” said Mark Bartolomeo of Verizon.