Organic electrochemical transistors (OECTs) are used in research and diagnostic applications due to their facile manufacture, scalability, and biocompatibility. In these devices, the source–drain current upon gate voltage application depends on ion concentration in the electrolyte. This study investigates whether an OECT can be employed to monitor bacterial growth since it is known that the concentration of charged species increases in bacterial cultures during growth. A poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate‐based single‐well OECT, compatible with long‐term incubation of bacterial cultures, is fabricated. It is shown that the growth of Salmonella alters the transfer characteristics of the device and demonstrates how it can be applied to monitor growth in real‐time by recording the source–drain current at gate voltage +0.5 V. The signal can also be measured in filtrates of bacterial cultures, devoid of bacterial cells. This suggests that the signal originates from charged metabolic products. Bacterial biofilm formation does not alter the device response. This proof‐of‐principle study presents OECT recordings as an alternative to optical methods, allowing bacterial growth to be monitored in transparent and opaque media alike. By measuring metabolic products rather than bacterial cell multiplication, insight into the stationary phase and other nondividing states may be obtained in the future.

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The problem of choosing only one relevant safety performance indicator for the purpose of comparing and assessing road safety situations has been the subject of many recent research studies. This paper shows the concept of creating a composite exposure index based on available data. The procedure of creating a model for calculating this indicator is based on the analysis of quality of individual exposure indicators and the size of their impact on the direct safety performance indicators – number of road crashes and their consequences. The following four models (TOPSIS EQUAL, TOPSIS CRIT-IC, PROMETHEE EQUAL, PROMETHEE CRITIC) for determining weighted coefficients of the individual indi-cators that participate in the creation of the composite exposure index have been analysed in this paper. The method used for defining the composite exposure index is the “high-efficiency method” based on which the final shape of the model for defining the composite exposure index has been defined. The main aim of this paper is to create a model for defining the composite index of traffic exposure. The final outcome is to provide an opportuni-ty to evaluate and rank traffic safety levels based on the unique road traffic risk.