Subway riders may be frustrated with the system's consistent service delays. 

But the head of New York City Transit says repairs have actually helped stabilize the subway. 

Since last summer, workers have inspected more than 11-thousand signaling locations and repaired more than 13-hundred switch defects. It's all a part of the nearly 840-million dollar "Subway Action Plan." 

Andy Byford says commuters may overlook the work being done because of all the delays caused by construction. 

"There's so much work going on that we have flaggers out there, we have people working on the track. So the customer's perspective is probably that actually things haven't really improved too much yet because there are delays literally because we are doing the work. But to not do the work is not an option - we've got to get it done." 

Beyond temporary fixes, the MTA is also trying to fund a nearly 40-billion dollar plan to overhaul much of the subway system over the course of a decade.