The first shock came when the price hit $2. Then it hit $3. Then $4. Today, many Americans are braced for a time when the price of a gallon of gas tips through the $5 mark for the first time.

But soaring gas prices are not just confined to the US. In Canada a gallon will set you back $5.75, $6.75 in Australia, and approaching $9 per gallon in the UK, according to data compiled by Bloomberg.

As a result, people are looking for cheaper ways to travel. And one of the ways they are doing that is swapping four wheels for two.  According to the US Motorcycle Industry Council, for example, sales of new motorcycles and scooters were up 8.8% for the first quarter of 2012 compared with the same period last year. Scooters alone were up 16.9% over last year.

It is easy to see why. They are perfect for whizzing around congested cities. They are easy to ride, easy to park, and typically cheap to buy and run. From the streets of London to New York, Taipei to Shanghai, the scooter is leaving other modes of transport in its dust.

But despite their jaunty image, and associations with glamourous Italian socialites, scooters have a darker side.  Their small gasoline engines are highly polluting, and they are very noisy. The Environmental Protection Agency in the US says that its studies “show that motorcycles have much higher emissions than cars”.

Modern cars have emission control equipment, such as catalytic converters, that is impossible to fit into the smaller exhaust of a scooter.  So, although they use less petrol, they actually produce more air pollution than a car over the same distance.

“A motorcycle emits as much hydrocarbon in 10 miles as a car driven 850 miles,” says the EPA. “These emissions form smog and contain toxic compounds such as benzene.”

Swap station

But there could be an answer. Electric scooters provide all of the convenience of their dirtier cousins, but are almost silent, and do not release any emissions from the vehicle. They are already huge in China, where there are an estimated 120million electric bikes and scooters on the roads.

And now big manufacturers are getting in on the act. Honda, BMW, Peugeot and VW have all shown off concepts, although few have, so far, come to market. Even fewer have found mass appeal.  But that could soon change. Earlier this month, automotive giant Daimler announced plans to bring an electric scooter to market by 2014 (it has already started production of an electric bike).

“The decision in favor of the escooter has been made,” said the firm’s Dr Joachim Schmidt  at the launch. “With this step, we are adding a further important component to our smart mobility concept for urban mobility in the future.”

The smart escooter, as it is known, is currently being developed and refined. But when it was first unveiled at the Paris Motor Show in 2010, the firm said that it would have a top speed of 28 mph (45km/h) and a range of 62 miles (100km) on a single charge.

That may sound ideal for the city commuter, but there are still bumps in the road before these two-wheelers can displace the scooters of old.

One of the biggest is the small batteries used to power the scooters. These are enough for short hops in cities, but for heavier users they just don’t currently cut it.  

“Most of our customers are fleets, and they use this type of scooter for sushi and pizza deliveries” says Gilles Chelard, in charge of R&D for Matra, a European manufacturer of small electric vehicles. “For a fleet it’s a nightmare to charge more than one or two scooters on the same plug, with a tangle of cables.”

Relatively small battery capacities and recharging times that can run into hours compound the problem. That is why Matra has come up with an ingenious battery swapping station, that they are calling Bat’Lib. The version they showed me is about the size of a refrigerator, but has 10 small doors on the front. The idea is that a driver simply swaps out a battery on an electric scooter for a fully charged one, as easily as you could swap the battery on your mobile phone.

“This swapping station allows us to charge …nine batteries at a time, because there is always one spare slot for charging a battery that is being swapped” says Chelard.

On most scooters the battery is located under the saddle.  To swap it, a rider lifts up the seat, and pulls the battery out. He or she swipes an ID or touch card against a reader on the swapping station, to identify themselves; a door pops open and the rider dumps the empty battery. As soon as he closes the door, another one pops open revealing a fully charged battery to plug back into the scooter. The whole process takes just 10 seconds.

It is similar - in concept at least -to systems that are currently being tested for electric cars by Californian company Better Place.  As batteries can account for a huge proportion of the weight of an electric car, its systems have to be much larger and automated. Its switch stations look like automated car washes. Drivers pull in, and then sit tight as their battery is replaced.  

They are currently being tested in Israel. And, although they have huge potential benefits, widespread deployment is a long way off. The cars and the swapping stations have to be designed to work together, and if we are ever to see them replace the ubiquity of petrol stations, then car manufacturers will have to come together to agree a common battery design.

Scooters, on the other hand, are much easier - the small size of a scooter battery makes it a quick and easy swap, by hand.

