The MTA is rebuilding the signal system on the G line — the Brooklyn-Queens crosstown route whose equipment dates to the 1930s — under a roughly $368 million modernization that will make the G the third subway line fully converted to Communications-Based Train Control (CBTC), after the L and the 7.

The trade-off for riders is disruption now in exchange for reliability later. The MTA has scheduled additional weekend and segment closures on the G through 2026 to let crews install the new system, after a full-line suspension in the summer of 2024 allowed the bulk of the early work to be done at once.

What CBTC does

The G’s existing fixed-block signals divide the track into sections and can only tell whether a block is occupied, a constraint that limits how closely trains can follow one another. CBTC tracks each train’s position continuously and communicates with it in real time, allowing tighter, safer spacing and — the MTA argues — more frequent and more reliable service. The L line was the first to be fully converted, followed by the 7. The G is next in line.

The work matters for about 160,000 riders who use the G on an average day, per MTA figures. The line is the only non-shuttle route in the system that never enters Manhattan, connecting Court Square in Long Island City to Church Avenue in Brooklyn and threading neighborhoods — Greenpoint, Williamsburg, Bedford-Stuyvesant, Park Slope — that have grown sharply in population.

The contract and the contractor

The signal modernization is being carried out under a contract held by Crosstown Partners, a joint venture whose members include the signaling firm Thales and the electrical contractor TC Electric. The MTA values the work at roughly $368 million.

The G project is one of several CBTC efforts moving in parallel. The MTA is also pushing modern signals onto the Queens Boulevard line, and in December 2025 the board approved a contract to bring CBTC to the Fulton and Liberty Avenue lines carried by the A and C — replacing signals first installed when those lines opened in 1936. The authority has said congestion-pricing revenue is helping fund the broader signal program in the 2025–2029 capital plan.

The schedule has slipped

The G modernization has not been smooth. The project is running behind its original timeline, and the MTA’s forecast completion has slipped to roughly 2029 — about two years later than earlier targets. To keep the work moving, the authority opted for concentrated shutdowns rather than relying only on overnight and weekend outages.

That choice drew pushback from Brooklyn elected officials, who objected to the volume of planned disruptions. The MTA announced additional weekend closures running through the end of 2026, a stretch that will leave a significant share of weekends without normal G service. The authority’s argument is that doing the work in larger blocks is faster and cheaper than stretching it across years of partial outages — and that the payoff is a line that, once converted, runs more reliably for the neighborhoods that depend on it.

Why it matters

Signal modernization is the least glamorous and arguably most consequential work the MTA does. Decades-old equipment is a leading cause of subway delays, and replacing it is slow, disruptive and expensive. The G’s conversion is a test case the MTA points to when defending the pain of closures elsewhere: the L and 7 conversions, the agency says, demonstrably improved service once finished. Whether the G’s 160,000 daily riders judge the trade worthwhile will depend on how cleanly the 2026 closures land — and whether the new completion date holds.

Verification

Frequently Asked Questions

What is CBTC and why does the G line need it?
Communications-Based Train Control is a modern signaling system that tracks trains continuously and lets them run closer together more safely than the fixed-block signals installed on the G in the 1930s. The MTA says it improves reliability and capacity.
How much does the G line project cost and who holds the contract?
The signal modernization is a roughly $368 million project. The contract is held by Crosstown Partners, a joint venture that includes Thales and TC Electric.
When will the work be finished?
The MTA's forecast completion has slipped to around 2029, roughly two years later than earlier targets, with continued weekend and segment closures in the interim.
How many people ride the G train?
About 160,000 riders use the G line on an average day, according to the MTA.