perhaps) 10% of the road new construction (i.e. USD 20-30 billion/year) could be SO diverted with some attendant (but possible bearable) consequences in terms of deteriorating overall road infrastructure quality.25 Land use and environmental limitations on road infrastructure expansion, although most of the road new construction is driven from replacement requirements to maintain an existing stock of road capital. Improvements in road maintenance and management (especially efficiency enhancements through ICT/telematics, and extension of infrastructure life): Up to (perhaps) 5% of the road new construction (i.e. USD 10-15 billion/ year) could be saved in the long run. INFRASTRUCTURE TO 2030: TELECOM, LAND TRANSPORT, WATER AND ELECTRICITY - ISBN 92-64-02398-4 - © OECD 2006 4. KEY FACTORS DRIVING THE FUTURE DEMAND FOR SURFACE TRANSPORT INFRASTRUCTURE Reduced safety and security requirements (which appear unlikely). Generally, with the exception of in-vehicle communications/navigation/ tracking technologies, these concerns are unlikely to add substantially to road new construction requirement (especially as road safety is a major influence in road design). Conversely, there are factors that might increase the requirement for new construction on roads. These include: Increased costs associated with road construction in urban and congested traffic areas (e.g. right-of-way acquisition, environmental mitigation, integration with other infrastructures). Generally, it is believed these are factored into the model. Greater than anticipated geographic (spatial) dispersion of economic activity, especially in Big 5 and developing countries. It is difficult to imagine greater spatial dispersion occurring within existing industrialised countries, but such a phenomenon might occur within the larger of the Big 5 and developing countries (e.g. China, Russia, Brazil). Higher than anticipated growth in vehicle ownership and traffic use. Generally, a flexible upper-limit has been placed on vehicle ownership (vhp) and average distance 