Mobile data terminal
Introduction
In public transportation, a mobile data terminal (MDT) is usually a portable computer added to a vehicle to assist with information and data management at service delivery. The computer may be a laptop, tablet computer, or customized hardware. There are many applications for MDTs such as managing paratransit trip manifests, collecting passenger and fare data, communicating with dispatch, and trip routing. MDTs are an effective tool for analyzing operations data in greater detail than with traditional pen-and-paper data collection.
The field of MDTs is rapidly developing, although their use in public transit dates back at least 25 years [1]. Software is often customized based on an agency procurement, but standard packages are available through software businesses specializing in the transportation industry. MDTs may operate entirely standalone while in the field or may use various wireless communication technologies to communicate with dispatch or a centralized server for information exchange.
Applications
MDTs may serve one or many functions, with the possible applications continuing to grow as the field develops and new ideas are introduced. MDTs can be helpful in managing flexible transportation services. They are also commonly used in fixed route and paratransit services for specialized applications.
Common functions
- Automated Vehicle Location (AVL): MDTs can incorporate AVL by processing location data to transmit to a central server or dispatch. Some are also capable of serving as a GPS-based navigation assistant for vehicle operators [2].
- Communication: MDTs can be used to facilitate efficient communication between vehicles and dispatch. This is often in the form of pre-programmed text messaging, which uses significantly less bandwidth than voice calls over a two-way radio system. Agencies operating a large number of vehicles may find that pre-programmed text messaging is an effective tool to reduce voice traffic.
- Data entry and information management: A common use for MDTs is to collect a greater level of operating detail than might otherwise be possible. This may include the ability for the driver to categorize passenger counts by fare type (half-fare, adult, passes, etc.), by boarding or disembarking location, and so on. Some systems can incorporate some level of automation, such as pairing a location from the AVL component with the passenger fare type.
- Paratransit trip management: Manifests or trip itineraries can be managed through an MDT as opposed to a traditional paper list. By incorporating wireless communication MDTs have the ability to update an individual driver’s manifest to reflect changing trip requests.
Many of these applications can combine to maximize efficiency. For example, a paratransit management software application can allow two-way text messaging to dispatch, allowing for real-time response for changing circumstances. The software package can also serve as a data management tool, providing accurate and detailed statistics for service delivery.
Hardware
MDTs were traditionally customized and highly specialized hardware, even as recently as 2007. As consumer technology in touch-screen and tablets developed, agencies have begun to procure off-the-shelf hardware with customized software applications. The industry has adapted by developing software which can run on various consumer platforms.
Communications
In the most basic application, a mobile data terminal is fully self-contained with no communication to other systems or the Internet. Agencies are more commonly using MDTs that communicate with a central server.
One form of information sharing is to download information from the MDT on a limited basis. This could be done traditionally by physically connecting the MDT with a desktop computer or to a central server and downloading information, commonly as part of end-of-day procedures. Agencies can also utilize a local wireless network to download data from MDTs as they are returned to a central point, such as the service garage.
An option that is growing in popularity and cost-effectiveness is the ability to transmit data in real-time using the cellular data network. Agencies can purchase an MDT or consumer tablet computer with the capability of connecting to a cellular data network. Depending on configuration and data plans, the MDT may transmit data essentially continuously or on a programmed frequency such as once an hour. Cellular phone providers may offer Government agency data plans unavailable to the consumer market.
References
- ↑ TCRP Synthesis 70 “Mobile Data Terminals”. Harman, Lawrence J. and Shama, Uma. Harman Consulting Boston, Massachusetts. 2007.
- ↑ TCRP Synthesis 91 “Use and Deployment of Mobile Device Technology for Real-Time Transit Information” Schweiger, Carol L. TranSystems Corporation Boston, Massachusetts 2011.