ORIGINAL PAPER ROckfall risk MAnagement assessment: the RO.MA. approach Claudia Mignelli • Stefano Lo Russo • Daniele Peila Received: 27 December 2010 / Accepted: 1 March 2012 / Published online: 20 March 2012 Ó Springer Science+Business Media B.V. 2012 Abstract The analysis of risk for vehicles and drivers as a result of rockfall on a road is relevant to design management in geotechnical engineering. This process is very complex due to the large number of parameters involved. In this paper, we discuss risk analysis and management procedures for roads subject to rockfall phenomena. To this aims, we are proposing a quantitative method (the RO.MA. approach). We developed an abacus to define the threshold values of acceptable rockfall risk for a given road. Rockfall risk is calculated using an Event Tree approach and compared with the abacus thresholds to evaluate road safety and the need for additional protective measures to reduce the risk to an acceptable level. The approach was successfully applied at a test site located in Bard, Aosta Valley, north-western Italy. Keywords Rockfall  Landslide  Risk assessment  Event tree  Road management  RO.MA. approach 1 Introduction Transportation corridors in mountainous regions are often susceptible to major hazards, such as landslides and rockfalls. The analysis of risks associated with these types of instabilities is a complex operation requiring the precise assessment of hazard and the vulnerability of vehicles on roads along the foothills (Budetta 2004, 2010; Budetta and Poggi 2010; Fell et al. 2008a, b). The fulfilment of safety requirements for mountainside routes often requires the implementation of protective measures and devices to control and manage rockfall. The positive effects of such measures should be evaluated in terms of risk reduction. The effects of these instabilities can include damage to vehicles, injury or death of drivers and passengers, and economic loss due to road closure (Duncan and Norman 1996). The cost of a car accident can be very large because it may involve the death or hospitalisation of the driver and C. Mignelli  S. Lo Russo (&)  D. Peila Department of Land, Environment and Geo-Engineering (DITAG), Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin, Italy e-mail: stefano.lorusso@polito.it 123 Nat Hazards (2012) 62:1109–1123 DOI 10.1007/s11069-012-0137-1