# Survey of Smart Parking Systems
## 5 Algorithms or Methods Implemented in SPS  
The analysis of the set of primary documents made it possible to identify the most common algorithms and methods implemented in SPS. These were grouped by type of algorithm, i.e., static, dynamic, and real-time algorithms. In addition, other types of algorithms were explored, many of which were implemented in a single work.  
A number of studies did not present the description of a particular algorithm or method, but rather described VDT or characterized some SPS without going into detail as to which method or algorithms it used; these were detected and classified as no data (ND).  
\begin{table}
\begin{tabular}{c c c} \hline
**VDT** & **Advantages** & **Disadvantages** \\ \hline IRS & Very accurate measurements of information. & Need to be installed on the road, so they are difficult and expensive to install. \\  & Can send information in real time. & Are sensitive to ambient pressure and temperature. \\  & & Require more frequent maintenance than other VDTs. \\ \hline  & & Require frequent maintenance as they are exposed. \\ ORS & Very accurate measurements of information. & There are better suited to closed or controlled \\  & Can send information in real time. & environments than to public roads. \\  & & Some, such as RFID, require devices in vehicles for \\  & & vehicle identification. \\ \hline  & & Expensive and installation cost are high. \\ RSU & Very accurate measurements of information. & Needs devices in vehicles (OBU) for communication \\  & Can send information in real time. & with RSU. \\  & & Due to their complex infrastructure, they are better \\  & & suited to closed and small car parks. \\ \hline  & No installation or maintenance costs. & \\ CS & Can send information in real time. & Sensed information depends entirely on user cooperation. \\  & A large number of parking slots can be sensed & Measurements of the information may not be accurate. \\  & if the set of users is large. & An initial volume of information for the training of \\  & & models is required. \\ PM & No installation or maintenance costs. & Its operation is based on a prediction. Such information \\  & & may not be accurate. \\  & & & Cannot send information in real time. \\ \hline  & & Dependence on information from a third party, usually \\ DFTP & No installation or maintenance costs. & without any manipulation of this information. \\  & & & Information obtained may not be accurate \\ \hline \end{tabular}
\end{table}
Table 10: VDT principal advantages and disadvantages.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline  & **PRS** & **PGIS** & **CITS** & **CAPS** & **AGS** & **EVPS** & **DS** & **APS** & **Total** \\ \hline IRS & 6 & 6 & 0 & 6 & 0 & 0 & 5 & 0 & 23 \\ ORS & 29 & 31 & 0 & 29 & 3 & 2 & 41 & 8 & 141 \\ RSU & 1 & 2 & 0 & 1 & 0 & 0 & 1 & 3 & 8 \\ CS & 1 & 3 & 23 & 1 & 0 & 1 & 0 & 1 & 29 \\ PM & 0 & 0 & 0 & 0 & 0 & 0 & 6 & 4 & 10 \\ DFTP & 2 & 4 & 0 & 1 & 0 & 0 & 1 & 3 & 11 \\ WD & 10 & 2 & 2 & 1 & 3 & 12 & 0 & 22 & 40 \\ Total & 49 & 47 & 25 & 39 & 6 & 15 & 54 & 39 & 274 \\ \hline \end{tabular}
\end{table}
Table 11: Relationship between the type of VDT (rows) and type of SPS (columns).