# Research of Park and Ride Parking Spaces Tiered Pricing Methodology Based on Subway Ride Distance
## 2 Materials and Methods  
### Survey Design  
The survey questionnaire employed an SP survey approach, encompassing three primary segments: Current Status of P&R Travel, Mode Choice Preferences, and Personal Characteristics Survey. To enhance the credibility of the data, an illustrative depiction of P&R services was presented before the commencement of formal questioning, ensuringthat respondents without prior P&R travel exposure could grasp a lucid understanding of P&R services. The questionnaire was made public on platforms such as WeChat and Questionnaire Star and was used to collect data. Interested viewers could click on the link to fill out the questionnaire, and in order to be able to collect enough data, after verifying the validity of the questionnaire, we offered a cash incentive to the respondents who completed the questionnaire. The questionnaire survey lasted for two weeks, from 16 March to 30 March 2023. A total of 711 questionnaires were collected, with 592 valid responses, resulting in an effective response rate of 83.3%. The sources of questionnaire data are illustrated in Figure 2. Data analysis results indicate that fewer than 42% of the respondents had engaged in P&R travel. The initial section of the questionnaire focused on the current status of P&R travel. It included questioning whether respondents had previous P&R travel experience, the purposes of their trips, and the relative importance of several factors influencing their travel choices. These factors encompassed travel time, P&R parking fees, travel comfort, road traffic conditions, and more. Furthermore, respondents with prior P&R travel experiences were specifically queried about their most recent P&R travel encounter. The questionnaire's section Mode Choice Preferences is a central focus of this study. We designed this part with an orthogonal arrangement involving two parking pricing options for P&R facilities (fixed and tiered) and three total travel distances: short (4 km), medium (10 km), and long (20 km). Within these settings, we presented respondents with ten scenario-based questions [34]. Each scenario offered four travel choices: private car, metro, taxi, and P&R services. To simplify the scenario, we assumed that all car trips headed to a public parking lot near their destination for parking. A schematic diagram of the scenario is depicted in Figure 3.  
Participants were informed about the travel attributes associated with each mode, including travel time, costs, walking/cycling distance, and the likelihood of available  
Figure 3: Schematic diagram of P&R travel process traveling scenario. Figure 2: Statistics on the sources of questionnaires. parking spaces at the P&R facility. In order to align the attributes as closely as possible with real-world scenarios, we determined the settings of some of the attributes that could be observed such as parking cost and walking distance by means of a field survey. The rest of the attributes such as fuel cost and travelling speed were determined by reviewing the relevant information and literature. The set rules are outlined in Table 1. It should be noted that under the tiered pricing strategy, a significant increase in parking prices caused some travelers to stop travelling by P&R [24], which in turn caused the probability of there being an available parking space in P&R to rise. However, the interviewees in this study have not experienced P&R trips under the tiered pricing strategy. To help them make a more accurate judgement, we drew on P&R parking demand survey data and the price elasticity of P&R parking demand from previous studies [33; 35]. Using the formula (probability of having an available parking space in P&R = P&R parking demand/number of P&R parking spaces) we set the probability of there being an available parking space in P&R in our scenarios to be 50% under the fixed pricing strategy and 90% under the tiered pricing strategy.