ALARP is a consortium of companies and universities from 5 European countries: Italy, Germany, Great Britain, Austria and Israel. This topic concentrates on conceptual models for warning / alerting signals and devices with ergonomic man-machine-interfaces (HMI). Safety of railway workers is a serious concern of most industrialized countries. Surface transport workers are facing very high risks since they often operate without service interruptions. The railway situation is even more peculiar, since vehicles are constrained to tracks and therefore drivers have much less margins to react in case of emergencies and therefore workers are much more exposed to injuries and fatalities. This vision is supported by many analyses and published reports - Most staff fatalities and serious injuries continue to be as a result of being hit by a train; - Most staff member deaths occurred in open line accidents, whereas most serious injuries to staff members were incurred in accidents in stations. Therefore safety requirements for railway trackside workers are very strict and necessary. In Germany today stationary railway automatic track warning systems (ATWS) are being used at railway construction sites. ALARP (A railway automatic track warning system based on distributed personal mobile terminals) is project partially funded by the European Commission whose goal is the study, design and development of a safety-critical Automatic Track Warning System (ATWS) for railway track-side workers