# Detecting Urban Mobility Structure and Learning Functional Distribution with Multi-Scale Features
## 5 Discussion
### The Spatio-Temporal Pattern of Travel  
To analyze the travel time patterns of Haikou City, we counted orders from different communities by the hour, separately for weekdays and weekends, as shown in Figure 8. On weekdays, the travel volumes of Type I and Type II communities display similar time-distribution patterns with slight numerical differences. From 00:00-03:00, volumes stay low; 04:00-06:00 sees a gradual rise; and a small peak emerges at 6:00-9:00. Volumes remain high and stable between 9:00 and 15:00, climb again to another daily peak at 15:00 and 18:00, and then decrease from 18:00 to 21:00.  
Over the weekend, the difference in travel volumes between Type I and Type II communities narrowed compared to weekdays. The travel demand in Type II communities rises, and both types see a peak at 18:00. This might be due to Haikou's tropical monsoon climate, where high daytime temperatures prompt residents to schedule leisure activities for the cooler evenings.  
Daytime temperatures are relatively high, leading residents to schedule their leisure activities during cooler evening hours. The order quantities for Type I, Type III, Type IV, and Type V in the community remain at a lower level, both on weekdays and weekends, consistently ranging between 0 and 200 orders. The volatility is also low, with no significant fluctuations at either the upper or lower extremes, indicating that travel demand in this area is relatively low and stable.  
To explore the characteristics of each community, we calculated the average travel distance, average travel time, and average travel speed for different communities, as  
Figure 8: Travel time of communities.  
shown in Figure 9. On weekdays, the travel distance in most communities is greater than that on weekends, with Type III, Type IV, and Type V communities exhibiting longer travel distances compared to Type I and Type II communities. It can be attributed to the centralizing urban structure of Haikou, where Type I and Type II areas encompass various functions such as commerce, culture, administration, and residential purposes. Residents in these areas do not need to travel long distances for daily activities. In contrast, residents of Type III, Type IV, and Type V communities need to commute long distances to reach their workplaces. However, on weekends, residents tend to choose leisure, entertainment, and other nearby destinations, resulting in shorter travel distances.  
In terms of travel time, communities of Type I, Type II, and Type IV on weekdays have shorter travel times compared to their corresponding communities on weekends, while Type III and Type V communities show the opposite trend. This is because, on weekdays, residents have a clear travel purpose due to work, leading to shorter travel times in Type I, Type II, and Type IV communities. Conversely, residents in Type III and Type V communities need to commute longer distances on weekdays, thus resulting in longer travel times compared to weekends. On weekends, people's travel purposes are more diverse, and the travel time is relatively more flexible. As a result, travel speeds on weekdays are higher than on weekends across all areas.