Cruising for parking again: Measuring the ground truth and using survival analysis to reveal the determinants of the duration

To effectively address the challenges posed by parking searches, accurate quantification is essential. This paper introduces a novel methodology to collect unbiased ground truth GPS data on parking search behaviors. Using a mobile application, we tracked the exact starting point, chosen parking spot, and final walking destination of over 3,000 trips in Germany from 2021 to 2023. Our findings indicate a mean parking search duration of 1.5 min (in large city centers 1 min and 53 s), a figure notably lower than previous survey-based estimates. This discrepancy suggests potential biases in traditional parking search surveys, possibly stemming from negativity bias. Our research employs a competing-risks survival analysis model to investigate factors affecting parking search duration simultaneously across different categories: Free, Paid, and Illegal parking. This enables the model to examine how the driver's choice between Free, Paid, and Illegal parking interacts with and influences the parking search duration. Furthermore, our duration dependency analysis, facilitated by a time-varying baseline hazard, reveals that prolonged search duration tends to make drivers more flexible toward less optimal parking options. This inclination is particularly evident for Paid parking, indicating that as the search duration extends, drivers increasingly consider Paid parking alternatives. Typically, drivers prioritize Free parking and opt for Paid options only after unsuccessful initial searches. This behavior underscores the notion that the coexistence of Free and Paid parking in urban areas might grow parking search traffic. Additionally, our data shows that approximately 5% of journeys end in Illegal parking. In these journeys, drivers often predetermine their choice of Illegal parking, as evidenced by the significantly shorter average search duration for these cases and the result that the likelihood of Illegal parking is not affected by the previous search duration.