1 . I was desperately nervous about becoming car-free. But eight months ago our car was hit by a passing vehicle and it was destroyed. No problem, I thought: we’ll buy another. But the insurance payout didn’t even begin to cover the costs of buying a new car—I worked out that, with the loan (贷款) we’d need plus petrol, insurance, parking permits and tax, we would make a payment as much as £600 a month.

And that’s when I had my fancy idea. Why not just give up having a car at all？I live in London. We have a railway station behind our house, a tube station 10 minutes’ walk away, and a bus stop at the end of the street. A new car club had just opened in our area, and one of its shiny little red Peugeots was parked nearby. If any family in Britain could live without a car, I reasoned, then surely we were that family.

But my new car-free idea, sadly, wasn’t shared by my family. My teenage daughters were horrified. What would their friends think about our family being “too poor to afford a car”？(I wasn’t that bothered what they thought, and I suggested the girls should take the same approach.)

My friends, too, were astonished at our plan. What would happen if someone got seriously ill overnight and needed to go to hospital？(an ambulance) How would the children get to and from their many events？(buses and trains) People smiled as though this was another of my mad ideas, before saying they were sure I’d soon realize that a car was a necessity.

Eight months on, I wonder whether we’ll ever own a car again. The idea that you “have to” own a car, especially if you live in a city, is all in the mind. I live—and many other citizens do too—in a place that has never been better served by public transport, and yet car ownership has never been higher. We worry about rising car costs, but we’d be better off asking something much more basic: do I really need a car？Certainly the answer is no, and I’m a lot richer because I dared to ask the question.

3 . Traffic Management

Traffic lights are key tools for regulating traffic now.They are not, however, perfect.Drivers exchange the traffic jams that would happen at unmanaged crossings for a pattern of stop-go movement that can still be annoying, and which burns more fuel than a smooth passage would.

Creating such a smooth passage means adjusting a vehicle's speed so that it always arrives at the lights when they are green.That is theoretically possible, but practically hard.Roadside signs wired to traffic lights can help get the message across a couple hundred metres from a crossing, but such signs are expensive, and are not widespread.Margaret Martonosi and Emmanouil Koukoumidis at Princeton University, and Li-Shiuan Peh at the Massachusetts Institute of Technology, however, have an idea that could make the process cheaper and more effective.Instead of a hardwired network of signs, they propose to use mobile-phone applications.The driver must load the team's software, named SignalGuru, into his phone and then put it on a special thing attached to the inside of his car's windscreen, with the camera lens （镜头） pointing forward.SignalGuru is designed to detect traffic lights and track their status as red, yellow or green.It broadcasts this information to other phones in the area that are fitted with the same software, and — if there are enough of them, the phones thus each know the status of most of the lights around town.Using this information, SignalGuru is able to calculate the traffic-light schedule for the area and suggest the speed at which a driver should travel in order to avoid red lights.

Tests in Cambridge, Massachusetts, where five drivers were asked to follow the same route for three hours, and in Singapore, where eight drivers were asked to follow one of two routes for 30 minutes, revealed that SignalGuru was capable of predicting traffic-light activity with an accuracy of 98.2% and 96.3% respectively, in the two cities.This was particularly impressive because in Cambridge the lights shifted, roughly half-way through the test, from their unbusy schedule to their afternoon-traffic schedule, while in Singapore lights are adaptive, using detectors fixed under the road to determine how much traffic is present and thus when a signal   should change.In neither case was SignalGuru fooled.

Fuel consumption fell, too —by about 20%.SignalGuru thus reduces both annoyance and fuel use, and makes going back and forth to work a slightly less horrible experience.

A warning system to prevent people from falling asleep while driving     1     ( introduce) at the China International Fair for Trade in Services. It can judge whether the driver is sleepy     2     monitoring how long the driver’s eyes close or if his or her head drops.     3     the driver enters a state of tiredness, the system will immediately sound an alarm until the driver’s eyes reopen.

9 . On paper, hydrogen（H2）looks like a dream fuel. Coal, oil, and natural gas produce carbon dioxide, which warms the earth when burned, Hydrogen produces pure water. Hydrogen packs more energy into less space than a battery（but certainly less than petrol）. Also, empty tanks（燃料箱）can be refilled with hydrogen much faster than refilling empty batteries with electricity.

While in practice, things are trickier. Storing a meaningful amount of hydrogen gas requires pressing it several hundred-fold. Changing it into the liquid form is another option, but it should be cooled to-253C. Both processes require a heavy and strong tank. While a 700 bar tank is acceptable for a city bus or a truck, adapting it for use in small vehicles is very difficult because the pressure during refilling would be too great.

The solution? Powerpaste.

A German team of researchers, led by Marcus Vogt, have come up with an interesting "powerpaste", which can store hydrogen energy at atmospheric pressure, ready for release when needed. It is so named because it comes in tubes and looks like toothpaste（牙膏）, not in its traditional form of gas.

The main ingredient（原料）of the paste is magnesium hydride, a substance that reacts with water to form hydrogen. The escaped hydrogen can then be directed into a fuel cell, where it reacts with oxygen from the air to produce electric power.

Refueling is very simple, as instead of going to a filling station, drivers and riders can simply replace an empty tube with a new one and refill the water tank.

Given that powerpaste only begins to break down at temperatures of around 250℃ it remains safe even when a vehicle stands in the baking sun for hours.

However, we will have to be patient. Just because researchers have succeeded in developing a new fueling way does not mean that we can expect to see such vehicles on the road anytime soon. It will indeed be several years before this concept is turned into reality.