For all their attractions, electric cars can be hard to justify on a practical basis. Factors like a comparatively high initial cost -- and a limited ability to make long trips -- cut into their viability as mass-market transportation.

But runabouts like the Hiriko, a two-seat microcar prototype designed specifically for urban car-sharing programs, offer a promising solution to gaps in today's transportation network. Short-distance car sharing with electrics could help bridge the gap between a commuter's home and mass transit -- the so-called first-mile problem -- or from mass transit to the workplace, the last-mile problem.

"The first- and last-mile problem has been growing steadily during the last 50 years as cities expanded," said Elizabeth Deakin, professor of city and regional planning and urban design at the University of California, Berkeley. "It's often just too far to walk to a mass-transit station."

A decade ago, researchers at the MIT Media Lab in Cambridge, Mass., began considering alternatives to car-pooling, bicycle-sharing, shuttle buses and other approaches that had failed to gain wide acceptance. The Smart Cities Research Group, led by William J. Mitchell, who died in 2010, imagined a tiny EV, intended purely for car-share use in the city, as a way to address some of the challenges emerging at the crossroads of transportation, housing and workplace location.

The project recently advanced from theoretical to commercial with the creation of the Hiriko Driving Mobility Group. A consortium of auto parts suppliers in the Basque region, the group worked with MIT and the Spanish government, which has supplied $18.5 million of the total estimated $87 million budget. The Hiriko name stems from Basque words meaning "from the city."

Jose Manuel Barroso, president of the European Commission, introduced an early version of the Hiriko Fold in January, calling it a "systematic solution to major societal challenges."

Now a trial manufacturing run has begun at Vitoria-Gasteiz, Spain, an hour south of Bilbao. Twenty vehicles have been completed for display and testing, said Carlos Fernandez Isoird, general coordinator of the Hiriko group, in a telephone interview. Three versions are on the way: the Fold; the Alai, a convertible; and the Laga, a small truck.

At first glance, the Hiriko Fold resembles other electric microcars. But the podlike EV comes packed with features. Most notable is the hinged body, which can retract its front and rear modules, shrinking the 8-foot-long car to a scant 5 feet when it is parked. About 3 1/2 Folds fit in a typical parking space.

Like the postwar Isetta ultracompact, the Fold has a front hatch that houses the windshield and doubles as the car's sole door. Another urban adaptation: The Fold's four wheels each turn 60 degrees left or right, enabling the car to spin on its central axis -- or even travel sideways, to make parallel parking a snap.

The city car's designers replaced the conventional steering wheel and the brake and throttle controls with a device like an airplane's yoke. Push the stick forward and the car will speed up; pull it back and the car will slow down. Move it left or right to make turns.

The production Fold will weigh less than 1,100 pounds and will be powered by lithium-ion batteries for a maximum range of about 75 miles. The four in-wheel electric motors have a total output of 20 horsepower, good for a top speed of 31 mph. The design successfully withstood in-house crash- and safety-testing this year, Isoird said. "In the summer, several of the first production lot will be sent to a couple of European cities to begin tests by potential customers," Isoird said.

The Fold is scheduled to go on sale in 2013 for around $16,400. Hiriko will also sell the EV as "snap-together" modules to cities, where local workers can assemble them for fleet use.

The group's plan is to sell the Fold to municipalities, including Barcelona, Berlin and San Francisco. Meanwhile, transport managers in the Basque biosphere reserve of Urdaibai, the Spanish island of Ibiza, Hong Kong and Florianopolis in Brazil have inquired about shared-use car systems.