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RTD integrates Positive Train Control into commuter trains

RTD is first in the nation to integrate Positive Train Control (PTC) technology in the actual construction of a rail system. The technology will be used on the new FasTracks commuter transit rail systems.


RTD's PTC system is undergoing testing along the University of Colorado A Line. RTD is one of the few transit agencies, nationally, to meet Congress' original Dec. 31, 2015 deadline to integrate this technology in commuter service. Congress recently
extended the deadline to Dec. 31, 2018.

The American Public Transportation Association said only 29 percent of the nation's
commuter railroads would meet the Dec. 31, 2015 deadline.

See the Positive Train Control fact sheet here.

PTC provides a number of safety benefits:

• Prevents unsafe speeds on train track
• Prevents train-to-train collisions
• Keeps trains from unsafely crossing rail switches (rail redirects)
• Helps stop train-caused injuries to maintenance workers who are on or near
  tracks

How PTC works

PTC prevents these types of accidents through the use of a complex GPS and
communications-based system called I-ETMS. The message delivery system for this technology is underground fiber optics placed along the alignment.

GPS verifies the position of the train so that the train "knows" what speed is appropriate to follow on different parts of the alignment. For example, if a train operator is approaching a curve too fast, the system will identify it. See more about how it works in the infographic below.



Train operators will be given a signal to stop the train if:

• They are traveling too fast
• Another train is stopped on the tracks ahead
• Maintenance crews are out working on the alignment

If the operator does not respond within eight seconds, the train will automatically slow to a stop.

The Rail Safety Improvement Act originally required all Class I and commuter rail lines in the country to integrate PTC into existing railroad systems by Dec. 15, 2015. But most railroads are unable to meet that deadline, so in October Congress passed an extension to Dec. 31, 2018. President Barack Obama signed the bill into
law on Oct. 29.

PTC was nationally mandated in 2008 after 25 people were killed in a train-to-train collision. The collision was caused by a train operator's failure to abide by a red light signal in Chatsworth, Calif. The collision could have been prevented by PTC
technology.