Combining AVL/APC technology

Many public transit systems rely on automated passenger counters (APC) to calculate ridership, justify future funding and optimize planning for their agencies. APC can improve planning and scheduling as well as help reallocate resources to correspond with demand. Using APC as a stand-alone system can provide reports per stop, door, trip, or route and line.

However, combining an APC system with an automatic vehicle location (AVL) system gives greater functionality to an agency. The benefits include real-time stop and route identification, as well as more flexibility with trip add-ons or re-routes.

If an agency uses a stand-alone APC system in parallel to a separate AVL system, it may become expensive to maintain due to the use of two separate systems. The agency would need to maintain a second database for data import and a separate reporting system. In addition, the cost of training staff on two different vendor systems may lead to higher project management expenses and prolong the successful operation of the agency's resources.

What is the solution?

It is important for any agency to analyze the different APC solutions available on the market today. It is also important to evaluate vendors to find a company that can provide a combined APC and AVL system. Some vendors provide active sensor technology on the bus or light rail vehicles as their only option for accurate APC. However, laser sensor technology today has advanced to a new level.

Nowadays, vendors offering combined active and passive sensor technology give agencies a cutting-edge advantage. The most advanced sensor to date is the IRMA 3-D sensor and analyzer.

An APC or AVL system can only be as accurate as the data that is maintained in the scheduling database. It is recommended that agencies use a survey tool to generate accurate scheduling information and maintain the database. The survey tool can calculate the mean values for stop positions and distances. The data can then be analyzed and generated with the APC system. The onboard computer of an APC system should be able to analyze distances and update scheduling automatically.

Data Security

Today, the latest technology for secure data transfer is by WPA2. Integrating APC and AVL as a combined system will require the most secure method of data transfer. This should be outlined in the agency's RFP as the information uploaded to the central system needs to be conducted on a secure network.

WPA2 is based on the Robust Security Network (RSN) mechanism, which provides support for all of the mechanisms available in WPA. WPA2 is the strongest form of wireless security, and should be the preferred technology of transit agencies choosing to utilize a combined system.

TCRP Study

The 2008 Transit Cooperative Research Program study (http://onlinepubs.trb.org/onlinepubs/tcrp/tcrp_syn_77.pdfX) provides a global in-depth overview for analyzing passenger counting systems. The study includes several agency testimonials and personal experiences with a stand-alone APC system as well as combined AVL and APC systems. The study reveals that a combined system has been proven to be far superior.                                                    

A featured case study showed how Dallas Area Rapid Transit (DART) successfully equipped 115 Light Rail Vehicles (LRVs) with a CAD/AVL system, and are currently working on an additional 48 Super LRVs that will have a combined CAD/AVL and APC system. Both systems are provided by the same vendor giving DART one data import system and one report system. According to DART officials, the main advantages of this technology, include real-time passenger reporting; reporting by load, vehicle, route and line; one system source for reports and data; flexibility with trip add-ons or re-routes; minimizes amount of hardware on vehicle; maximizes the reporting functionality with special events or detours; and improved schedule adherence as capacity is doubled over the next few years.

Advantages for train operators and controllers are that DART train controllers can track trains throughout the service area and get updates at 20 second intervals, increasing their ability to manage circuit tracking and the adjustment and displaying of station dwell times for the train operator so that the train stays on schedule.

Advantages for DART passengers are that its customers will be shown accurate "next train" arrival information at designated stations and customers will hear a consistent and precise automatic announcement that includes current station arrival times.

The combined AVL/APC technology provided to DART was procured from INIT Innovations in Transportation, a turnkey integrator and provider of advanced ITS and computer integrated technologies for rail, fixed-route bus and demand-oriented vehicles.

Andreas Rakebrandt is director of business development, North America Automatic Passenger Counting for INIT.