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Culver Line Signal Modernization: Details About the Project

Culver Line Signal Modernization will improve reliability and resiliency of service. We’re also using the opportunity to make additional station improvements.

Location: Brooklyn
Project type: Signal modernization
Project status: In progress

We’re improving service and stations with the Culver Line Signal Modernization by:

  1. Modernizing signals
  2. Upgrading interlocking systems and equipment facilities
  3. Making station repairs

Signal modernization involves improving two related parts of the system: the signaling equipment itself, and the interlocking equipment. This project will improve service along 4.7 route miles of subway track, across 12 subway stations.

What we're updating

Signaling equipment

The new signaling system will use technology known as CBTC, or communication-based train control. CBTC tells us more precisely where a train is at a station and between stations, so we can safely run trains more quickly and closer together. It’s also more resilient, so you should see fewer service disruptions.

Signal work we're doing:

  • Replacing all of the 70-year old signals with modern signaling
  • Installing a new CBTC system overlay on this section of the Culver Line
  • Adding three new signal facilities: at Ditmas Av, Bay Parkway and Avenue X

Interlocking equipment

We’ll also be installing solid state interlocking equipment, or SSI. This provides much more specific diagnostic information so we can fix problems more quickly. This includes:

  • Building a new relay room to house the new signaling equipment
  • Reconfiguring and replacing old interlocking at Ditmas Av
  • Replacing rail and switches in place with the same configuration at Avenue X
  • Adding two new interlockings south of Church Av 

Benefits of these upgrades

The Culver Line monthly on-time performance between June and December 2019 averaged just 67%, compared to a systemwide average of above 81%. This project aims to improve that performance. 

The Culver Line will be the fourth in the transit system to get modern signaling, following the L, 7, and Queens Blvd lines. Here’s how we’ve seen service improve on these previous projects:

  • In March 2018, only 55.5% of 7 trains arrived within 5 minutes of their schedule. We activated CBTC in the winter of 2019 and by March 2019, trains were on time 91% of the time.
  • We've had CBTC on the L train since 2012 and the average monthly on-time performance for 2019 was 92.1%.

What’s been done so far

Modern signaling

  • Completed steel and concrete floor installation at Ditmas Av Signal Facility 
  • Completed steel installation at Bay Parkway Communication Interface Room and poured concrete floor on both levels
  • Completed piling and grade beam installation at Avenue X Signal Facility
  • Completed clipboard survey/layout
  • CBTC equipment layout survey is in progress


  • Construction of relay room completed
  • All signals relay raks have been delivered to relay room
  • All signal cables have been installed and are being terminated 
  • 80% wayside signal equipment has been installed