Human Perceptions of Vehicle Turning Intention:

34 All pedestrians, drivers and cyclists regularly make predictions on where they think an 35 oncoming vehicle is intending to travel, so that they can successfully and safely navigate road 36 systems. Despite the importance of these predictions, the effectiveness of this process is 37 currently poorly understood with all existing research being focused on predictions from in38 vehicle technologies. This paper therefore investigates how well observers are able to predict 39 a vehicle’s turning intention as it approaches an intersection and explores the explanatory 40 variables involved in the success of this process through a logistic regression analysis. An 41 interactive touch screen experiment was developed so that people’s predictions about turning 42 intention could be investigated. The data set has been created with over 100 participants 43 attempting to predict a number of vehicles’ turning intention. 44 The key findings of this study are that people are very good overall at predicting 45 turning intention with approximately 90% median success rate when vehicles are between 0 46 and 20 meters (0-21.9 yards) away from the intersection, but with a substantial fall to 47 approximately 70% median success rate when the vehicle is between 30 and 50 meters (32.848 54.7 yards) away. Other key explanatory variables include both vehicle specific factors (e.g. 49 use of indicator lights) and crucially the intersection layout, providing valuable information 50 on the relationship between intersection design and road safety. 51