## 3 Objectives  
As explained in the previous section, the systems and services for people with special needs that are allocated to improving the accessibility and safety of public transit by highway require infrastructure components, such as positioning systems, components for providing information, and mobile communications systems. These components are deployed in different parts of the transit network, such as stops, stations, and vehicles. In the context of urban transit, this deployment can be achieved because urban areas have electricity, mobile communication coverage, and an urban architecture that facilitates this deployment. However, this infrastructure, which is specific to adapted public transit, must be maintained, which implies a greater cost of transportation infrastructure maintenance, especially for the components located at stops and stations due to deterioration from massive use, vandalism and environmental causes.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Special Needs User Type** & **Required Intelligent Services** \\ \hline Users with limited mobility (require a wheelchair or assistance to walk, cannot use fingers or arms, coordination problems, limited strength). & Systems to assist in boarding and disembarking from the vehicle. Alert system in adapted vehicles. Traveler information systems with adapted terminals. Adapted wireless payment systems. \\ \hline Users with visual impairment. & Systems to assist in boarding and disembarking from the vehicle. Route assistant. Adapted wireless payment systems. \\ \hline Users with hearing impairment. & Mobile device-based information systems based on visual perception. \\ \hline Users with cognitive impairment. & User-friendly traveler assistant that provides simple and easy to understand information. \\ \hline \hline \end{tabular}
\end{table}
Table 1: Special needs user groups and required system types.  
The objective of the proposed system is to assist travelers with special needs in the context of highway transportation in urban areas and in isolated rural areas to improve accessibility and safety. In addition, its operation does not imply a significant increase in the maintenance cost of transportation infrastructure. To accomplish these objectives, the system will provide a set of smart services that are deployed in transportation infrastructure. These services are developed by using components that are typically available in transportation infrastructure, as shown in Figure 1. The services provided are autonomous, affecting the normal functioning of the equipment, processes, and services in the transit network as little as possible, that is, the system is transparently integrated into the conventional highway-transit infrastructure. Moreover, the services developed with the proposed system can be deployed alongside traditional support services for public transit travelers, based on audio prompts and information panels. Another aspect is the primary role of vehicles, given that their facilities--both hardware (on-board equipment, sensors, and communication components) and software (positioning system, operation control system, and payment systems)--provide the basic data that are required for the various deployed intelligent services, _i.e._, a stop-accessibility monitoring system, an adapted payment system, and a route assistant.