# A Spatio-Temporal Schedule-Based Neural Network for Urban Taxi Waiting Time Prediction
## 3 Materials and Methods
### Urban Functional Distribution and Points of Interest in the City  
An important assumption of our modelling approach to complement the temporal distribution of human activities developed in the previous section is to consider functional distribution and spatial structuration of the city layout. In order to do so, we consider the distribution of function points of interest in the city. Without the loss of generality, and to experiment our approach with real data, we integrate Gaode City POIs (points of interest) categorized into different activities, namely: shopping, education, commercial residences, scenery, catering, public facilities, transportation facilities, life, sports, medical treatment, government and accommodation. Based on this data, we further subdivided POIs into 19 kinds of categories: catering services, public facilities, shopping services, commercial housing and living services, sports leisure services, scenic spot, science and education, cultural services, private clinics and hospitals, accommodation services, government agencies and social organizations, companies, ATM and Banks, car parks, large commercial circle, large hospitals, large venues and bus stations. Since the activity rules of some large venues, such as stadiums, science and technology centers, children's palaces, large business districts, scenic spots and general hospitals are highly dependent on holidays and working days, scenic spots, large venues, large business districts and general hospitals are classified as special functional areas. The resulting categories of POI are shown in Table 1 below.  
Since the same geographic grid location may have multiple functional area properties, the three dimensions of comprehensive economic gravity, traffic accessibility and financial connection network will determine the dominant weight of each type of functional area based on the premise of the interaction intensity of factors such as inter-city economic flow,  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Functional Area Category** & **The Name of the Table** & **Whether Special Functional Area** \\ \hline Public utilities & poi\_02\_gonggongsheshi & No \\ Bus stations & poi\_18\_gongjiaozhan & No \\ Parking lots & poi\_14\_liaotongsheshi & No \\ ATM and banks & poi\_13\_ATMyinhang & No \\ Government agencies and social groups & poi\_11\_zhengfujigou & No \\ Sports leisure services & poi\_06\_tiyuvuixuan & No \\ Life services & poi\_05\_shenghoufuwu & No \\ Food and beverage services & poi\_01\_canyin & No \\ Private clinics, specialist hospitals & poi\_09\_zhuangkeyiyuan & No \\ Companies & poi\_12\_gongsijye & No \\ Accommodation services & poi\_10\_zhusufuwu & No \\ Business residences & poi\_04\_shangwuzhuzhai & No \\ Science and education culture services & poi\_08\_keliawownuha & No \\ Shopping services & poi\_03\_gouwu & No \\ Scenic spots & poi\_07\_fengjing & Yes \\ Big business circles & poi\_15\_davingshangguan & Yes \\ Large hospitals & poi\_16\_davingsiyuan & Yes \\ Large venues & poi\_17\_davingschangguan & Yes \\ No function area category identification & poi\_19\_null & No \\ \hline \hline \end{tabular}
\end{table}
Table 1: Urban functional areas categories.  
people flow and logistics, and capital (financial) flow [28]. According to the weight of the dominant position in the unit grid, the functional area category of the grid is determined as its highest priority.