KS2: pupils have to consider their own involvement in environmental management (PoS 5a, 5b). This could be done by carrying out an investigation of traffic in their local area, based on QCA Unit of Study 20. Many schools are involved with "Safer Routes to School" - if not, you could draw on the materials and links available on their website: www.saferoutestoschools.org.uk KS3: a case study could address KS3 PoS 5b "explore the idea of sustainable development and recognise its implications for people, places and environments and for their own lives". The Cambridge Futures website is an excellent place to start: www.cambridgefutures.org (click on "Futures 2" followed by "The Transport Options".
Pupils could investigate the advantages and disadvantages of each option and describe their preferred option. GCSE and A-level students could explore the impact of transport systems on the growth of towns and cities.
Or they could investigate the impact of changes in transport by researching a case study such as London's Docklands: www.museumindocklands.org.ukindex.html