Transport represents one of the worlds biggest polluters and the largest consumer of oil. With energy prices high, there are lots of developments happening to move transportation away from it's reliance on oil. The jury is still out whether any of this is making a difference, but a start has to be made somewhere & now is as good a time as any.

 Cars are used all over the world and are no longer just the preserve of developed countries. As the 

 people of China and India gain prosperity, the first thing desired is a car. The vast majority of the 

 world's cars are currently powered by an internal combustion engine running either petrol, or to a

 lesser extent diesel. Alternatives are discussed below :

Hybrid cars, like the Toyota Prius, are rapidly gaining popularity. They have electric motors supplemented by a small internal combustion engine, with a computer working out the optimum way to use these energy sources, whilst keeping the battery charged. Fuel consumption is improved, especially in stop-start driving scenarios. However, the overall cost of including two power plants in a vehicle, plus the energy required to produce and dispose of the large battery banks makes some question the overall environmental credentials.

Hydrogen cars are currently being developed by large motoring firms lke BMW, Honda and others. Whilst some see hydrogen as the solution, it requires an expensive fuel cell to convert the energy into electricity to run the car. Hydrogen also has both significant storage challenges as well as the fact that it currently required large amounts of energy to be produced.

Electric cars have been around for years but are plagued by the driving range provided before the battery needs re-charging. A lot of effort is going into increasing range and reducing vehicle weight, alongside entrepreneurs setting up networks of charging stations with the facility to swop battery packs for longer journeys. PHEVs (Plug-in Hydrid Electric Vehicles) offer a compromise whereby the batteries can be recharged at any electrical outlet to reduce the amount of time the internal combustion engine is needed.

Compressed air cars  are not a new idea; as far back as 1687 compressed air was being considered as a way to propel vehicles. Compressed air has many industrial uses where it is driving motors, so it's not a massive leap to include it in a car design. Whilst there is still a long way to go to overcome safety, distribution and storage difficulties, some believe this is the way forward, especially for city driving.

 Planes are are very large and growing source of both pollution and energy consumption. 

 Environmental damage is increased at high altitudes, and there's an ongoing debate about aircraft

 fuel effectively being subsidised as no government has worked out a way to tax it without pushing 

 re-fuelling to anther country.

With oil prices at high levels, very few airlines will have a viable business model, and especially the low-cost airlines could start to become a thing of the past. It's ironic that just as many countries are expanding airport capacity, air travel looks to be returning to the preserve of the rich. Industry commentators talk about biofuels being the salvation of the airline industry but fail to mention how this will happen without driving up food prices and depleting soil.

 Trains, buses and trams can all be classified as 'mass transit' and have their place in integrated 

 transport policies. The vehicles themselves do produce pollution (if not locally, then at the power

 station) and use energy resources, but in a well-planned system will be far more efficient than

 individual cars. Early hydrid, biofuel and electric buses are being tested, removing local pollution,

 but this still means the energy source needs generating elsewhere.

 Cycling and walking remain the most efficient ways for humans to get around, and both are on 

 the increase, especially in developed countries. Town planners across the world are now

 prioritising the needs to cyclists and pedestrians, often to the detriment of private car drivers. This

 really falls under the 'conservation' theme, in that the best way to conserve energy is to remove

 the need to use a form of transport that requires an external energy source.