INFRASTRUTTURE STRADALI E SMART ROADS

INTRODUCTION TO THE COURSE

The roads in the history and evolution of design criteria. Functional aspects, road safety, and environmental issues. Design according to standards and performance-based design.

ROAD INFRASTRUCTURE

The new Highway Code and Decree of 05/11/2001. Functional classification of roads. Issues related to the classification of the existing road network. Roadway: Road section, platform, carriageway, road structure.

ROAD DESIGN BASED ON STANDARDS

Ministry of Infrastructure and Transport, Decree of 05/11/2001: Functional and Geometric Standards for Road Construction. Organization of the road: cross-section, additional lanes, marginal elements. Widening on curves for vehicle alignment and obstacle visibility. Road axis geometry: Design speed. Tire-pavement contact and coefficient of friction values. Clear visibility distances (stopping, overtaking, lane changing). Vehicle movement along circular curves. Minimum radius and criteria for determining platform slope, tangents, variable radius transitions, design, and insertion of clothoid transitions. Compositional criteria of the road axis and planimetric coordination of geometric elements. Criteria for the placement of speed bumps. Maximum uphill and downhill gradients. Critical length of speed bumps. Insertion of lanes for slow vehicles. Vertical transitions. Planimetric-altimetric coordination. Design speed diagram. Speed of slow vehicles. Route verification based on speed diagrams.

PERFORMANCE-BASED ROAD DESIGN

Safety performance: The European and national framework for road safety. The European directive on road infrastructure safety management and Decree of 15/03/2011. Direct measurement of road safety and performance indicators: Road safety performance functions. Poisson and Negative-Binomial distributions. Accident modification factors. Empirical Bayesian correction. Estimation of expected accident numbers and comparative analysis of different design solutions. Direct and indirect costs of road safety. Discounting of costs and benefits. Benefit/Cost ratio. Indirect measurement of road safety: Design speed, commercial speed, legal speed limit, and operational speed. Operational speed and geometric consistency of the route. Pre-project safety checks. International reference framework and National Guidelines.

Traffic performance (overview): Evaluation of service level for design practice. HCM model (single-lane or separated-lane roads). Free-flow speed. Measures of effectiveness (average travel speed, percentage of time in congestion, traffic density).

ROADWAY FURNISHINGS

Definition of the clear zone and protective zone. Safety performance related to road margins: clear zone width, slope of embankments, presence of fixed obstacles, types of safety barriers. Influence of vehicle characteristics and swerving modes on collision consequences. Types of safety barriers to be adopted, their location, related complementary works, regulatory framework, and EN standards.

SMART ROADS

The physical and digital infrastructure of Smart Roads. C-ITS solutions day 1.0 and beyond. Definition of Operational Design Domain and Service Level of Smart Roads. Levels of vehicle autonomy on the roads.

ROAD GEOTECHNICS (Overview)

Construction of the roadbed. Physical characteristics of soils. Particle size analysis. Soil composition: specific gravity, void ratio, porosity. Measurement of water susceptibility: Atterberg limits. Soil classification. Group index, CNR-UNI 10006 Classification. Volume of the roadbed solid. Area and volume diagrams. Compensation worksites.

ROAD PROJECT DEVELOPMENT

Design levels, basic cartography, alignment study. Executive design: typical sections, layout plan, project layout, layout of hydraulic presidio works, longitudinal profile, cross-sections, notebook of sections, and detailed volume calculation. Construction details of vertical transitions, construction details of art structures, general cartography, project report. Computer-aided design.