As urban populations soar, so does the pressure on transport systems. But our dependence on cars doesn't just clog up the roads - it damages the environment and uses up dwindling fossil fuels.

From Nepal to The Netherlands, 'Hands On' takes a look at innovative solutions to our transport problems.

Clean dreams - Germany

Most road vehicles are powered by fossil fuels - depleting them and causing pollution. An ever-growing demand for mobility will make matters worse. But in Munich, an airport bus may hold the key to the future. Instead of an internal combustion engine, it's powered by hydrogen fuel cells.

Hydrogen is one of the Earth's most common chemical elements, found in and produced from water - H₂O. What's more, it's a 'clean' fuel producing no carbon dioxide emissions.

The bad news is that fuel cells are expensive, the vehicles are slow and the hydrogen gas is heavy and bulky. There are also few filling stations that supply hydrogen fuel.

Now BMW have taken the lead and developed a prototype car that combines a normal combustion engine (for the moment) and a hydrogen fuel cell. It's called the duel-fuel car. These new cars are powered by liquid hydrogen, which takes up less storage space than gas.

BMW have produced fifteen prototypes that are roaming the streets of Hanover and Munich in a pilot scheme. With growing demand for cars around the world, carbon dioxide emissions must be reduced if the climate is to be protected. Hydrogen may eventually completely replace petrol altogether.

For more in-depth information from the Hands On team, visit their website.

On your bike - The Netherlands

For people living in the city of Amsterdam there's now an alternative to cars and buses - communal 'white' bikes.

Using a special key, cyclists pick up 'white' bikes from points around the city and drop them off at other designated points. The bikes are designed to be sturdy, unisex and, costing just half a dollar a ride, very cheap.

Unfortunately, cyclists can't deviate from designated routes and the scheme is so new its success is hard to gauge. But the word on the street is encouraging and the aim is to have 40 stands within the year and a permanent supply of 750 bikes.

For more in-depth information from the Hands On team, visit their website.

Electric cars - France, Liselec

Getting people onto a bike isn't always easy. It may be simpler to tempt drivers out of their own cars into pollution free models that can be shared or pooled for communal use around inner cities - cutting congestion into the bargain.

Liselec is a public transport scheme allowing both commuters and businessmen to share a pool of zero emission non-polluting electric cars to navigate around the city.

With only slight modifications to a Peugeot shell, an electric motor and cadmium battery supply can be fitted to the car. Electric cars can last more than ten years.

Like the communal bikes in Amsterdam, motorists must collect the vehicle from a central point but this time they can drive the car wherever they want.

For more in-depth information from the Hands On team, visit their website.

Where there's no road - Zambezi, Mozambique

In many developing countries a lack of transport and poor roads means people spend hours getting to market, school and hospitals.

In Mozambique the problem has been worsened by civil war. It not only wrecked lives but also destroyed much of Mozambique's infrastructure - in particular the roads that were laced with landmines.

As large numbers of people return to the countryside, safe roads are essential to improve people's lives and invigorate a shattered local economy. Funded by the UK Department for International Development the road project is rehabilitating 840km of feeder roads.

Local contractors who tender to the local authorities to rebuild particular stretches do the work. Unemployment is around 80% and there are few ways other than subsistence farming to earn money - so road building is an important source of extra income. Although workers are only paid around 1 US dollar per day, it's enough to save a little money.

But while the road has made it easier to transport goods to market and get children to school the numbers of people travelling between town and country has also grown. And so has the spread of infectious diseases like HIV.

Anxious to educate migrant workers about the health risks an outreach programme educates them about safe sex. Now the incidence of sexually transmitted diseases is less frequent and less serious.

For more in-depth information from the Hands On team, visit their website.

Generating current - Nepal

When 'Hands On' first visited Nepal two years ago the polluting diesel tempos - small three wheeler taxis - were threatening peoples' health and tourism. To combat the problem two small fleets of electric tempos were set up by local entrepreneurs.

The programme generated lots of letters from people interested in electric vehicles. It also provoked a reaction from the Nepalese people who were tired of choking on the fumes from the old diesel models and started a protest movement to ban them.

While the programme may have helped ban diesel vehicles the success of the electric tempos as a business proposition cannot be underestimated.

Two years ago Pushpa Pokhrel had a small fleet of ten tempos. Now he has 100 tempos, ten filling stations and employs around 230 people. He has orders for more than 100 more electric vehicles.

Equally exciting is the interest from neighbouring countries like India. But the biggest impact has been on the air quality in Kathmandu - a tangible benefit for locals tired of diesel fumes.

For more in-depth information from the Hands On team, visit their website.

A breath of fresh air

Although there's a long way to go before petrol- and diesel-fuelled transport is a thing of the past, scientists have come along way in developing the new cars of the future. And if hydrogen fuel can be made more efficient, cost effective and available at local filling stations, we may be on the verge of a cleaner petrol-free future.

For more in-depth information from the Hands On team, visit their website.