Crews rely on 1930s-era technology and — in some cases — paper maps to direct trains along those tracks when something goes wrong. Once it’s done, the transit agency will send 3 trains along Nostrand Avenue and 5 trains beneath Eastern Parkway. A report the MTA plans to publish on Wednesday lays out plans to fix two of the worst bottlenecks in the subway system — and identifies dozens of other pain points that cause daily headaches for millions of riders. Transit officials have studied ways to fix those bottlenecks for years, but they were just two of 70 locations identified in Wednesday’s report where the MTA could reduce train congestion. “We need to figure out how to unsnarl it, and that's what we're doing across the system to help move people faster.”