It pays to own an electric car in London. Why? Owners can drive in and out of the city’s central zone without paying the steep $15.50 (£10) daily congestion charge. That provision of the law led a lot of London commuters to buy bargain-basement EVs, such as the flimsy Indian-made Riva G-Wiz, which in a "Top Gear" test lost a battle with a table.

What’s more, since 2008, central London has been a “Low-Emission Zone,” which means that certain diesel-powered trucks, buses and large vans are “deterred” from driving in the city.

London Leaf taxi

That’s the way things are now, with 150,000 cars (95,000 of them private vehicles) entering the zone every weekday. Some electrics have plied the streets as taxis (see the Leafs above), but only in pilot programs. But London Mayor Boris Johnson is planning to rev things up by turning that entire downtown core into an “Ultra-Low Emission Zone,” admitting only battery electrics and unspecified “low-emission vehicles” by 2020. It makes sense, but a lot will depend on how the city defines low emission.

Johnson promises more than 1,600 hybrid buses for London by 2016 (330 are driving now). He also wants all of the city’s new black taxis to be zero emission by 2020.

The impetus for this isn’t hard to see: According to the ClientEarth green group, by European Union rules England’s capital city will have “illegal levels of air pollution until 2025.” ClientEarth notes that the city’s announcement comes just weeks before the U.K. Supreme Court hears its air-quality case against the British government. “Is this a coincidence?” the group’s Alan Andrews asks. “I doubt it.” The London Assembly says that 9 percent of city deaths are due to air pollution.

“Creating the world’s first big-city, ultra-low emission zone has the potential to be a game-changing moment in the quality of life in our great capital,” the bike-riding Johnson said. “This would deliver incredible benefits in air quality and stimulate the mass use of low-emission technology.”

Maybe. If the “low emission” category includes a lot of gas cars (that happen to produce fairly small amounts of smog and carbon dioxide), then it won’t be a big change. If it includes only hybrids that can run on batteries a lot of the time (such as the Chevy Volt) it will do more. The latter version would certainly do a lot to reduce the city’s infamous congestion (below).

London congestion

Andrews worries that the proposal will get watered down, as did the next phase of the low-emission zone to cut nitrogen dioxide emissions (it will only apply to city buses). The city is looking at options, and Andrews says to expect “noisy opposition from some taxi drivers, business and the motorist lobby.” He expects the ultra-low-emission zone proposal to be “quietly shelved.”

Some critics like the plan but don’t think it should be seven years down the road. Friends of the Earth wants faster implementation, better public transit, and encouragement for more people to ride their bikes. Green Assembly member Jenny Jones said that “leaving [the zone] as a project for the next mayor to deliver is a way of ducking responsibility for the problem we’re facing now….We need the zone now, with a zero-emission target.”

Of course, the popular Johnson could still be in office in 2020, since he was re-elected to a second four-year term in 2012 and a proposal to limit London mayors to two terms was defeated in Parliament. The guy’s not only popular, he gets away with things. According to, “One of the most astonishing things about Boris is that he has the ability to say anything and get away with it. He could argue that black was white, then argue the following day that black was black. We might think it odd, but then we shrug our shoulders, say ‘Well, it’s Boris’ and get on with things.”

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.

London to be an 'ultra-low emission zone' by 2020
An ultra-low emission zone for London by 2020.