Positive Train Control for Transit Rail

Positive Train Control (PTC)

The EMTRAC PTC System combines precise positioning technology with secure FHSS radio communication to incorporate key elements of Positive Train Control. The EMTRAC system includes Overspeed Protection, Collision Avoidance, and Stop-Bar Overrun—while also offering additional capability as described below.

When an equipped train exceeds defined safety thresholds, the EMTRAC system alerts train operators and central personnel. For all instances of exceeded safety thresholds, the EMTRAC system may also alert the train operator of the event on the in-cab Control Head.

If additional thresholds are reached, the trains can be set up to automatically slow down and/or stop while an alert is sent to all other trains.

The Central Monitor software saves a detailed log of designated events and train activity and may be configured to email these events to designated personnel on a periodic basis.

The EMTRAC system requires no costly in-track circuits to install or maintain, and it accurately reports train locations, even in difficult urban-canyon environments.

EMTRAC AVL Features

Central Monitor software displaying an equipped rail vehicle

Automatically locate specific trains, intersections, and rail workers with the click of a mouse.
Connect to signals and switches to enable display of current signal and switch states on map.
When specified events occur (such as speed violations), the system automatically alerts designated personnel—as they occur.
The system may be configured to automatically generate reports, which are then archived and emailed to designated personnel.
Activity logs may be automatically transferred and saved to the network while trains are at rail yards.
View Connectivity Logs, which show changes in network-connectivity status to help identify possible network issues.
Monitor signal-controller responses to priority requests to help verify proper system functionality.

EMTRAC AVL Benefits

Central Monitor software displaying an equipped rail vehicle

Expandability: AVL components may be added to existing EMTRAC system as agency budgets and schedules allow.
Ease of Installation: Minimal additional hardware is required because the AVL system interfaces with the same EMTRAC system components as those used for Transit Signal Priority or to implement elements of Positive Train Control.
Flexibility: Specific train classes (such as Light Rail Vehicles or Commuter Vehicles) may have individual detection zones assigned to them, which require that custom conditions be met before Transit Signal Priority is requested.
Security: The AES-encrypted FHSS radio signals utilized by the EMTRAC system offer superior range and unmatched security.
Accuracy: The advanced GNSS and inertial positioning ensures precise train location reporting—even in adverse conditions and environments.

AVL Data Sheet

Central Monitoring (PDF)

EMTRAC Central Monitor Displaying Stop-Bar Overrun Alert

The Control Head Alerts Operators of Excessive Speed

The EMTRAC system uses “Virtual Fixed Blocks” to designate allowable speeds for specific segments of track. These blocks can be customized on the fly to allow for special events or temporary speed restrictions.

When equipped trains exceed defined speed limits, both operations center personnel may be notified of the event by the Central Monitor software, which also saves a detailed log of designated events and train activity. Central Monitor may also be configured to email these events to designated personnel on a periodic basis.

As with all other defined safety thresholds, train operators may be alerted about excessive speed by the in-cab Control Head.

EMTRAC Technology Helps Ensure Open Rail Lines

“Virtual Moving Blocks” are used to ensure trains adhere to agency-defined block spacing. These moving blocks travel with their assigned rail vehicles, and the block lengths adjust based on train speed (or as calculated by braking algorithms).

When the EMTRAC system determines that two equipped trains are within the same block, train operators and central personnel are immediately notified—and further actions may be taken such as automatic slowing (by either ceasing propulsion, braking, or a progressive combination).

For more information about EMTRAC Collision Avoidance, please watch the video above.

EMTRAC Central Monitor Showing a Stop-Bar Overrun Alert

The EMTRAC system is capable of notifying designated personnel when trains run past precise stop locations, for example, at stations, intersections, and crossings.

Due to the urban environments where transit agencies seek to ensure pedestrian safety, accurate stop monitoring can be difficult to achieve. The EMTRAC system has proven its ability in the most difficult environments.

EMTRAC Videos

EMTRAC System video demonstrations of EMTRAC System capabilities, including Emergency Vehicle Preemption (EVP), Transit Signal Priority (TSP), transit rail safety, vehicle detection, and signal management.