Rail Vehicle Capability

EMTRAC Transit Signal Priority

Transit Signal Priority (TSP)

The EMTRAC system utilizes reliable GPS technology and secure frequency-hopping spread spectrum radio to enable both transit rail vehicles to request priority through signalized intersections.

Transit Signal Priority with EMTRAC TSP

Signal Priority without Traffic Disruption

Trains with the EMTRAC system transmit a priority request to equipped intersections when passing through detection zones. The intersection-control cabinet contains an EMTRAC Priority Detector, which relays the priority request to the signal controller.

EMTRAC is completely automatic and requires no driver interaction. Additionally, EMTRAC can be configured to allow priority control based on time of day, route-schedule adherence, passenger load, direction traveled, or other factors.

  • Conditional Signal Priority enables equipped vehicles to request priority only when agency-specified conditions are met (for example, when behind schedule by a designated amount of time).
  • EMTRAC ETA technology enables traffic agencies to implement Adaptive Signal Control for intersections, including those not equipped with adaptive-capable controllers or other third-party inputs. The ETA feature updates controllers of calculated time-of-arrival based on current traffic conditions (U.S. Patent No. 8,878,695).
  • Systems Manager interface allows easy customization for individual trains or intersections. For example, intersections along a route used for special events may hold priority requests for longer-than-usual time periods.
  • Detailed logs and reports show vehicle and intersection activity by date and time. The EMTRAC system may also automatically email periodic reports to specified personnel.
  • Priority-request start points may be based on time-of-day to allow for earlier controller requests during peak-period rush hours.
  • The benefits of TSP are well documented—and EMTRAC-system features reduce traffic disruption and unsynchronized signals
  • Installation and maintenance time is significantly less than with any other TSP system.
  • Offers the most advanced TSP features without requiring the latest signal-controller equipment.
  • Improves schedule adherence and headway times by enabling rail vehicles to request priority only when behind schedule.
  • Interfaces with Central Monitor software to enable transit personnel to track vehicle progress and activity.
Headway Maintenance

Train bunching—a trailing train catching up to a lead train—is a continual challenge for transit agencies. It is also a leading complaint of regular transit riders and a headache for those operating and managing transit services.

Headay maintenance is simplified with the EMTRAC system. Signal priority may be conditional—based on the amount of time since priority was last granted to a train traveling in the same direction. Alternately, equipped trains may utilize virtual moving blocks to notify train operators when a particular action should be taken (for example, trailing trains may slow to a designated speed or leading trains may operate in express or skip-stop mode) until the desired headway is re-acquired.

Information Sheets



Automatic Vehicle Location (AVL)

The EMTRAC Central Monitoring System enables supervisory personnel to remotely monitor train activity and progress in real time.

Transit Control Center with EMTRAC Central Monitor - Automatic Vehicle Location System

EMTRAC Central Monitor Displaying AVL Maps

With EMTRAC AVL (automatic vehicle location), equipped trains automatically transmit location and activity data to network-connected EMTRAC detectors in wayside cabinets. This data is displayed on central workstation monitors, showing vehicle movement on a map in real-time. Activity is also recorded in detailed logs for later review.

The components used for this system are the same as those used for basic EMTRAC TSP functionality, making it a cost-effective way to implement an accurate and reliable AVL system.

  • 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 states on map.
  • Automatically download and save activity logs from onboard VCUs while trains are at rail yards.
  • Configure system to automatically generate reports, which are automatically emailed and archived at specified intervals.
  • Automatically alert designated personnel—as specified events occur or on a daily/weekly basis.
  • Verify proper system functionality by monitoring signal-controller responses to priority requests.
  • View logs and generate reports that show changes in connectivity status to help identify possible network issues.
  • Ease of Installation: Central Monitoring System interfaces with existing EMTRAC TSP and EVP system components, requiring minimal additional equipment.
  • Expandability: Agencies can upgrade their existing EMTRAC systems with minimal effort, expanding the system as schedules and budgets allow.
  • Flexibility: Customize detection zones for specific train classes, and define the conditions under which TSP requests are transmitted.
  • Accuracy: The EMTRAC system utilizes advanced satellite and inertial positioning to ensure precise train location reporting—even in unfavorable environments.
  • Security: Frequency-hopping spread spectrum radio signal has superior range and utilizes AES encryption.

Information Sheets



Positive Train Control

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 Stop-Bar Overrun, Overspeed Protection, and Collision Avoidance—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.

Overspeed Protection
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.

Collision Avoidance
EMTRAC Central Monitor Displaying Stop-Bar Overrun Alert

EMTRAC Technology Helps Ensure Open Rail Lines

"Virtual Moving Blocks" are used to ensure that 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.

Stop-Bar Overrun
EMTRAC Central Monitor Displaying Stop-Bar Overrun Alert

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.

  • Central computers display real-time status and locations for all equipped vehicles.
  • Generate detailed status and activity logs, save them as reports, and export them as spreadsheet files.
  • Trains are equipped with Control Heads to visually and audibly alert operators of exceeded safety thresholds.
  • Interface with other EMTRAC-equipped vehicles (such as buses or fire-department vehicles) to help avoid collisions with non-rail vehicles.
  • EMTRAC software displays graphical locations in map view, aerial-photo view, or native EMTRAC view. It also enables the user to automatically locate specific trains and blocks with the click of a mouse.
  • EMTRAC Vehicle Computer Units can be set up to perform periodic diagnostic checks to ensure proper performance.
  • EMTRAC software enables operations personnel to record and save train activity for later review of key events.
  • Flexibility: Speed and distance thresholds are easily configured and implemented to allow for special events or temporary speed restrictions. Thresholds may include maximum authorized speeds, minimum allowed distances from other trains (as determined by speed or braking algorithms), and switch confirmation.
  • Reliability: Wireless communication is not hampered by adverse conditions, and the radio range allows for relatively few detector units.
  • Precision: Determine which tracks a particular train is on with position accuracy of +/- 24-inches or less.
  • Low Maintenance: Interface with existing switches and circuits without requiring costly in-track installations.
  • Timeliness: Improve route-schedule adherence by enabling designated trains (such as those on express routes) to request priority through signalized intersections.

Information Sheets



Automatic Logs & Updates

The EMTRAC Interrogator System enables transit agencies to automatically download activity logs from—and upload firmware and database updates to—equipped trains.

EMTRAC Interrogator System - Download TSP Activity Logs

Automatic Transfer of Logs at Rail Operations Center

The EMTRAC Interrogator System can be used at rail operations centers and maintenance facilities, as well as other locations.

As equipped trains return to rail yards, the EMTRAC Interrogator System utilizes secure frequency-hopping spread spectrum radio to download activity logs from onboard EMTRAC units. This data is forwarded to a server running the EMTRAC Central Monitor software, where the data may be viewed by authorized personnel.

  • Automatic Retrieval and Update: Wirelessly download activity logs from EMTRAC components, and automatically upload firmware or database updates to units that have not yet received the update.
  • Auto-Notifications: The EMTRAC software may be configured to email periodic activity logs to specified agency personnel.
  • System Monitoring: The EMTRAC software enables agency personnel to monitor connection status and history (between server and Interrogator as well as between Interrogator and EMTRAC components), and current RF-signal strength.
  • Communication Stability: Data is not lost in cases of network interruption, and data transfers resume from the point of interruption.
  • Low Profile: For external connections, the EMTRAC Interrogator Kit requires only 120 VAC power and Ethernet. All communication with EMTRAC train components is performed wirelessly.
  • Limitless Memory: By transferring activity logs to the system server, onboard EMTRAC components are able to continually store new log entries.
  • Timeliness: High communication rates enable fast data transfers, while offering many options for where to mount the Interrogator—such as near maintenance or washing stations.
  • Flexibility: The EMTRAC Interrogator may be mounted on wall, pole, or other structure, and multiple antenna options allow for reliable communication, even in high-interference environments.

Information Sheets