The most intelligent solution by a considerable margin is to behave intelligently.
Whether trains taking the strain of HGVs is economically or environmentally sound is worth debating. Assuming that anyone who questions the use of trains displacing road freight is making a solely financial judgement is misplaced.
Trains and the associated infrastructure also use energy.
The intelligent solution is to change behaviours to minimise total energy consumption rather than focus on one element (HGV transport). This may include:
- buy local and seasonal
- design and retrofit properties to minimise energy use
- repair, recycle and reuse - extend the life of clothes and consumer goods
- local not regional infrastructure - hospitals, schools, shopping centres - to minimise travel
- stop building out of town retail parks to reinvigorate local towns and communities
- make it easier and cheaper for people to move if changing jobs (eliminate stamp duty) to reduce commuting
Personally I favour the market to encourage change rather than additional regulation. This would involve reducing PAYE in favour of taxes on embedded energy, and taxing home energy consumption to encourage investment in more efficient homes.
In principle this could be tax neutral - those who are most responsive to change would benefit most, those reluctant to change current behaviours would face an significantly increased tax bill.
The only real questions are (a) how quickly does the transition from income tax to a carbon tax happen, and (b) which government (if any) would have the courage to implement such a radical scheme (probably none based on past performance).
The elephant in the room as always is population. David Attenborough noted in a recent talk that since he started broadcasting global populations have grown by 3 times. Unless this is actively addressed there is little prospect of avoiding climate change without a very unpleasant transition.