Ticket readers, single use


Magnetic-stripe, read-only

Magnetic-stripe readers are devices that read and decode the information contained on magnetic-stripe tickets. Please see the section magnetic-stripe tickets for information on the tickets themselves, and how they are used in the passenger transport sector for fare collection.

The core element of a magnetic-stripe reader is the reading head, which generates an electrical field. As the stripe passes over it, the reading head detects the variances in the magnetic field along the stripe. It decodes these variances into binary bits, which are transferred to the reader’s microprocessor for analysis and performing the relevant functions.

The reading head is normally fixed, and the card containing the stripe is passed over it. There are two fundamental ways of passing the magnetic stripe over the reading head:

  • The user manually draws the ticket across the head, either by “swiping” or by insertion and withdrawal. This is guided by an aperture or channel. While this is commonly used in many other sectors, it is rarely used in the passenger transport sector.
  • A motorized unit draws the card into the reader and over the reading head at a suitable speed, and then returns the card to the customer. This ensures that the ticket is fully inserted, and properly read. Almost all readers in the passenger transport sector use this principle.

The reading head can be either read only, or read / write. In practice, virtually all devices used for fare collection in the passenger transport sector are equipped with read / write heads, even if the fare products only require the card to be read.

The main internal features of a magnetic stripe reader are:

  • the reading head
  • the card transport mechanism
  • the reader’s microprocessor and its embedded programming
  • power supply
  • connectors and data exchange ports

These are packaged in a housing appropriate to the type of fare product and the actions required of the user. The package would normally include:

  • a display to give information to the user (balance remaining, ticket type, fault type)
  • LEDs or other color-coded visual display to indicate successful or unsuccessful validation
  • audio signal to indicate successful or unsuccessful validation, or in some cases to indicate fare product type (e.g. adult or child ticket)
  • optionally, a printer to print validation and usage data to the ticket
  • optionally, buttons for the user to select among tariff or fare zone options

Depending on the configuration, the reader may be:

  • fully self-contained with all of the required software for processing fare products, the fare tables, and memory to store the transactions, and a mechanism for the transaction data to be downloaded
  • merely a reading device, connected to a “master” device such as an ETM, which holds all of the fare collection software and data, and which receives and stores all transaction data
  • a hybrid, where some of the functionality can be done by the reader, but it still needs to communicate with the master device for baseline data and to send the transaction record after processing

Magnetic-stripe ticketing technology was dominant in the passenger transport sector through the 1970’s and 1980’s. In the past decade, though, magnetic-stripe technology for fare payment is becoming obsolete as it has by and large been displaced by smart-cards and applications on personal mobile devices.

Transit agencies that have switched from magnetic-stripe tickets to smart-cards have often retained the magnetic-stripe technology in parallel. This is mostly for low-value and disposable fare products, where the cost of a smart-card makes it unattractive to use for such purposes. Sometimes this is part of the transition period, as fare products as gradually migrated from magnetic-stripe technology to smart-cards. In others, it is seen as a permanent solution, although the magnetic-stripe technology may finally be phased out when the equipment reaches the end of its useful life and would need to be replaced.

Read-only applications are mostly required for:

  • Travel passes, both time-period and personal (employee, concessionary). The reader needs to verify that the ticket is current, is being used correctly (time of day, mode, location, etc.), and to record the transaction data for planning, administrative or reimbursement purposes.
  • Single-journey tickets, which have been issued and stamped elsewhere and now need to be validated for use on the current vehicle (e.g. on feeder services). The reader may also record the transaction data for planning, administrative or reimbursement purposes.

In practice, “read only” transactions usually involve read / write, even though there is no adjustment of the fare product data or decrementing of value. The reader will usually write data concerning the current validation to the stripe – e.g. date, time, route, boarding stage / zone. This may be used for subsequent boardings to identify linked trips, either for fare collection purposes or to assist network planning.

Benefits of magnetic-stripe readers are:

  • Facilitates the use of magnetic stripe tickets for a wide range of fare products.
  • Supports automated transfer validation.
  • Can integrate with other in-vehicle and at-station devices.
  • Provides a moderate level of security.
  • Transaction data can be generated, with extensive downstream potential.
  • The technology is used widely; it is supported by international standards.

Cautions with regard to magnetic-stripe readers are:

  • The technology is increasingly becoming obsolete for fare collection in passenger transport.
  • Cannot support secure electronic purse.
  • Machines need to be purchased and maintained.
  • Readers are rather expensive.
  • Consumables such as printer cartridges can be expensive.
  • The machines have many moving parts and complex electronics; this requires technical capacity of the operator, and has more risk of failures.

Bar-code reader

Smart paper tickets use two main formats:

  • Holographic images
  • Bar-codes

Please refer to the section smart paper tickets for details of the tickets and their application in the passenger transport sector.

Holographic images are for visual inspection by drivers/conductors and by revenue protection personnel. They are not intended to be machine-readable (at least not as used in the passenger transport sector) and hence there are no known cases of holographic image readers for vehicles or transit entry points.

Smart paper tickets with bar-codes are intended to be machine-readable, though. Bar-code readers are devices which scan bar-codes and decode the contained information for subsequent processing.

Bar-code readers are generic devices which pass information to other devices. They can be stand-alone units with cable or wireless connection to other devices, or they can be embedded in other devices (e.g. gates, fare-boxes).

In the public transport sector, barcode readers are used for the following applications:

  • To check the validity of passes
  • To check that validity of pre-issued travel tickets
  • To record the usage of various fare products
  • To activate other devices when validity is confirmed – e.g. gates, turnstiles
  • Inventory control on value stock
  • Additional security feature for ticket stock

Bar-codes tend to be used where the processing time is not critical to passenger flow or dwell times.

Benefits of bar-code readers are:

  • The devices are generic and mass-produced; this leads to a wide choice of supplier, and lower cost.
  • The technology is robust and well-established.
  • Bar-code readers can be integrated with other devices.
  • No moving parts, so inherently reliable.
  • Transaction data can be generated for downstream processing.

Cautions with regard to bar-code readers are:

  • Bar-code readers need to be purchased and maintained.
  • Customers may experience difficulty in lining up their ticket properly to scan the bar-code; this causes delays and frustration for the customer.

Applet reader for phone or PDA

Applets are small programs (applications). This section considers applets that reside on, or have been downloaded to, mobile phones and other portable devices (e.g. PDAs). See section machine-readable applets for information about applets and their application in the passenger transport sector.

“Near-Field Communication” (NFC) allows the user device and the transit reader to identify each other and hold two-way communication. As the name suggests, this type of communication requires the devices to be relatively close to each other (within a few centimeters). This is direct device-to-device communication. It does not use the GSM / GPRS facility of the user’s mobile device, and hence is secure, immediate, free, and is not vulnerable to communications service coverage or quality.

On the transit device side, payment with NFC is one of many options. The capability for communication with NFC devices is embedded in the existing ticket machines, card readers or gates / turnstiles. The software in the reader (or its master device) is adapted for the communications, data exchange and security aspects, and also for the validation and/or fare collection functionality with the applet.

At the scale and mode of use of NFC-supported fare payment, it is unlikely that there would be stand-alone NFC readers.  Nonetheless, if/as NFC payments become more established and achieve higher market penetration for transit fare payment, it is then possible that NFC readers will emerge, perhaps as devices that support both NFC-enabled mobile devices and contactless smart cards.

Benefits of applet readers are:

  • Enables the acceptance of applets on users’ mobile devices for fare payment and travel authorizations.
  • Relatively low cost to enable existing or new ticketing machines, card readers and gates to work with NFC-enabled devices.
  • Many smart-phones already contain an embedded NFC chip, which supports communication of encrypted data.

Cautions with regard to applet readers are:

  • This remains an innovative and developmental area; there is not yet the depth of practice and problem-solving experience as in other fare collection technologies.
  • The designers of the concept in the applet may not have paid sufficient attention to how it should work in practice, either on the technology side between device and reader, or the ergonomics of the transaction. This can leave the reader designer with substantial challenges to design a secure and efficient solution that respects the transit agency’s mode of operation.
  • The applet owner is frequently a third party, outside the control of the transit agency. While this may not be a problem at the level of the reader itself (communications and data exchange), there is still a need to ensure that the validation and fare collection software can work with the applet.
  • The requirements for back-office authorization, transaction records and clearing need to be factored in to the system design.
  • Many NFC-enabled devices work with different communications protocols. This can result in multiple detections of the same NFC device by the reader (finding it on each of the recognized communication protocols), and thus slower communications and transaction processing. 
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