Lexus: The hybrid debate blog

If hybrids were ever to go mass-market, it's likely the fleet would be highly varied in terms of engine types. Today, the hybrids with the highest levels of public awareness - such as the Prius, the Civic IMA and the various Lexus-h models - are all petrol hybrids. On UK roads, the only other type of hybrid vehicle is the diesel hybrid bus being run on a trial basis by London Transport. But tomorrow - at the latest by 2030 - we'll have a choice of petrol, diesel and bio-fuel hybrids. And probably also "fuel-cell hybrids", in which the principal power source is hydrogen, obtained either from filling stations, or reformed on-board from some other fuel.

However, with the exception of those fuelled purely by hydrogen, cars will not really be very different to those we drive today. They will still need to visit filling stations,which will probably run by the same companies. And our road infrastructure will be fundamentally the same. The driving experience will not really have changed - and that, I suggest, that is where the "hybrid problem" lies.

If we rely on technology, people's travel behaviour and choices won't change - we will just be driving cleaner cars and, if current purchasing trends continue, a lot more of them. Congestion will be terrible, with all the economic and social costs that brings.

It's easy to imagine a future in which we sit on the M25 in our zero-emission vehicles but don't move, because everything is completely congested. We will have solved one problem, emissions, while completely failing to address another that is equally important: mobility.

What's required is a "whole-system solution" - a mixture of technological "fixes", a new policy environment and a change in personal behaviour and attitudes. Some of the technology changes have been discussed above, and it is likely that the further forward you look - the greater the role that electricity will play. Whether this is generated on-board via hydrogen fuel cells, or stored using novel types of batteries with vastly better performance than those available today, is a moot point.

However, the technological fixes will happen no matter what. It's just a question of how rapidly and in what order. This will in part be driven by the policy environment. But what is really needed is a change in attitudes and behaviours around mobility. Without this, the policy environment will change slowly and we will not make any real progress. We will have the same roads, the same infrastructure, just much cleaner, more efficient cars, stuck in bigger queues. If we are really going to change for the better, it is not the technology that will do it - it will be people's attitudes and behaviours to transport.