Philadelphia's 10-year-old program to reward electric-vehicle owners with privileged curbside parking places appears to be running out of gas.

Two City Council members have introduced legislation to put a moratorium on new EV parking spaces pending a review of the program, which has triggered resentment among owners of conventional vehicles in congested neighborhoods.

The Philadelphia Parking Authority, rather than wait for a formal Council vote on a moratorium, has notified 12 residents already approved for parking spots that it would not install the special EV-only parking signs in front of their houses. Like visa holders snared in a surprise presidential travel ban, those permits are stuck in limbo until Council makes a new plan.

"The recipients of the 12 pending zones have all received letters explaining the moratorium and that their zones will not be installed until further notice," Martin O'Rourke, the Parking Authority's spokesman, said in an email. The moratorium was prompted by mounting residents' complaints to Council members over a 2007 law allowing owners of electric vehicles to apply for special reserved parking spaces, where they could install curbside charging stations. The law was sponsored by then-Councilman James F. Kenney.

The Parking Authority has issued only 56 EV permits since 2012; there were no applications the first five years. The permits are concentrated in neighborhoods such as Society Hill, Fairmount, and University City, where parking spaces are in short supply.

Philadelphia's EV parking law appears to be unique among large cities.  In 2014, Berkeley, Calif., approved a pilot program to award 25 permits for private curbside electrical chargers, but did not include parking privileges. San Francisco provides public curbside charging stations operated by credit cards. The fee includes the parking space along with the electricity.

Councilmen David Oh and Mark Squilla held a joint hearing Jan. 30 of the Committee on Streets and Services and the Committee on Global Opportunities and the Creative/Innovative Economy to address the EV parking crisis, where according to a transcript, they heard mostly complaints about the special parking arrangement.

"The current regulations provide an incredible benefit to a limited group of homeowners who happen to have public parking in front of their house," testified Robert Curley, director of the Society Hill Civic Association. He also said some residents objected to unsightly EV signs and chargers on the sidewalks.

The fee for a city permit for an electric-vehicle zone is comparable to what a business would pay to secure a loading zone, the Parking Authority says. Each  applicant pays a $50 nonrefundable application fee. If approved, a homeowner in Center City or University City will pay an installation fee of $250 or $500, depending on whether a currently metered parking spot is sacrificed.

On top of the installation fee, homeowners pay an annual Parking Authority fee of $150. The fees are lower outside Center City.

The homeowner must arrange for an electrician to install the curbside charging device, which requires a different set of permits and costs that typically total several thousand dollars.

But the price for the privileged streetside parking space is cheap compared with the cost of renting space in a commercial lot, which typically runs from $2,400 to about $3,600 a year in Society Hill, Curley said.

Squilla suggested that maybe the city should increase the annual permit cost to $5,000, which would "raise the awareness that you're really taking a parking spot off the street for everybody else to use."

Though any electric vehicle theoretically can park in a designated EV parking slot, the spots are practically private spaces because only the homeowner controls the electricity supply at the curbside recharging station.

In response to growing complaints, the city last year limited each block to four authorized parking spots of any kind, such as handicapped zones, loading zones, and EV parking, Richard Montanez, deputy streets commissioner, told the committee. If parking is permitted on only one side of the street, the block is limited to two special spots.

The Council members emphasized that they had nothing against electric vehicles, saying that they wanted to encourage clean energy, but that it might be better through community vehicle-charging stations.

On Feb. 2, Oh and Squilla introduced a bill that would enact a moratorium "pending Council's review of the impact of these spaces on overall parking availability and enactment of further legislation." The Committee on Streets and Services has tentatively scheduled a March 21 hearing.

In reality, a moratorium went into place immediately after the Jan. 30 hearing, without formal Council action. Council members instructed the Parking Authority to halt EV parking spots, even the 12 already approved.

"Right now, I believe we agreed to a moratorium on adding new ones," Squilla said, according to the transcript. "I'm sure everybody will be happy with that, except for the 12 or so that are pending."