ABSTRACT:Road transport has always played an important role in a country's growth and, in order to manage road networks and ensure a high standard of road performance (e.g. durability, efficiency and safety), both public and private road inventories have been implemented using databases and Geographical Information Systems. They enable registering and managing significant amounts of different road information, but to date do not focus on 3D road information, data integration and interoperability. In an increasingly complex 3D urban environment, and in the age of smart cities, however, applications including intelligent transport systems, mobility and traffic management, road maintenance and safety require digital data infrastructures to manage road data: thus new inventories based on integrated 3D road models (queryable, updateable and shareable on line) are required. This paper outlines the first step towards the implementation of 3D GIS-based road inventories. Focusing on the case study of the "Road Cadastre" (the Italian road inventory as established by law), it investigates current limitations and required improvements, and also compares the required data structure imposed by cadastral legislation with real road users' needs. The study aims to: a) determine whether 3D GIS would improve road cadastre (for better management of data through the complete life-cycle infrastructure projects); b) define a conceptual model for a 3D road cadastre for Italy (whose general principles may be extended also to other countries).
1* INTRODUCTIONMobility and transport represent two key components of economic development and human welfare of a country. Road transport promotes rural development, the transport and selling of agricultural products, industry and trade, the expansion of jobs, and access to health, education, and services (Parami Dewi, 2013). The role of roads is equally decisive at the urban scale, as they connect city parts and are a framework for the city structure (Sun and Chen, 2000). The number of reasons for people to travel between two locations (e.g. for work, leisure, family) has been increasing and road traffic has become very intense, a trend that will continue (World Highways. International Road Federation, 1990; Road Transport Forecasts, 2013): new roads are planned, existing road networks require daily maintenance, and safety, traffic congestion, and trafficrelated air pollution have also to be properly managed. The above requires inventories/information systems in which roads are properly identified, classified and described, and where geospatial data, administrative and technical-functional road features are collected, with the recent development of different specialist transport-related topics (e.g. Intelligent Transport Systems (ITS)) adding to the need for digital road data infrastructures to integrate and manage road-related information (Sandgren, 2004). Real-time sensing of traffic and of the road surface to monitor and analyse road phenomena (e.g. to check the status of the road structure o...
