 (freight and passenger) forecast over 2000-30 of 2.9% annual growth in vehicle transport use (vkm) has been produced - largely driven by rising vehicle ownership (as GDPpc rises), growth in underlying GDP, and assumptions about annual per-vehicle use. 32 Over the 2000-30 period, the model (vkm growth relative to GDP growth) indicates that road-use intensity (to output flow) will rise about 0.4% per annum. 33 A similar measure (vkm growth relative to road asset value) indicates that road-use intensity (to capital stock) will rise about 1.3% per annum. Other studies have looked at intensities of freight (tkm/GDP) and passenger (pkm/GDP) transport and found: For the United States (over 1960-98) a falling ratio of road ton-miles per $GDP.35 For other industrialised countries (over 1970-98) mixed results with: a falling ratio of road tkm per $GDP for Japan and the United Kingdom; a relatively stable ratio for Germany; and an increasing ratio for France and Sweden. 36 INFRASTRUCTURE TO 2030: TELECOM, LAND TRANSPORT, WATER AND ELECTRICITY - ISBN 92-64-02398-4 © OECD 2006 KEY FACTORS DRIVING THE FUTURE DEMAND FOR SURFACE TRANSPORT INFRASTRUCTURE For the United States and Japan (over 1970-2000) a falling ratio of passenger transport, while for the EU rising passenger ratios, and relatively stable ratios for freight. 37 In the absence of reliable cross-country data on freight (linking tkm to vkm by country) and passengers (linking pkm to vkm by country), there is no attempt to forecast freight (tkm) or passenger (pkm) transport volumes. It could be speculated that vkm growth (over 2000-30) will be higher than underlying pkm growth, since passenger occupancy per vehicle generally falls as vehicle ownership rates rise with rising GDPpc, and since freight growth might outstrip population growth. It could also be speculated that vkm growth (over 2000-30) will be lower than underlying tkm growth, as the latter (but not the former) is influenced by rising vehicle ownership rates, as the size/weight of trucks increase with GDPPC