By Marcus Leach
The state of London's underground system is being reviewed by a London Assembly inquiry.
With further strikes announced, coupled with recent disruptions and signal failures has forced an inquiry into the state of the system.
The Transport Committee has said it will examine all eleven lines to see why performance had declined, as well as why upgrades promised eight years ago were delayed.
The initial target had been to increase capacity by 2020, but that has slipped behind target, with the Jubilee, Northern and Piccadilly lines most affected.
Over the past four years the Jubilee line has had the worst problems, remaining closed on over 100 weekends in that time period.
The most recent problems were in April when on two consecutive weekdays passengers were stranded in trains when services were suspended for hours after signal problems.
It is not just the Jubilee line that has experienced problems this year, with nearly all other lines having reported signal failures and train faults since the start of the year.
The inquiry will also focus on the period since Transport for London (TfL) brought maintenance in-house in 2008.
"Londoners have been told for years that all the closures, disruption and billions of pounds spent will be worth it in the end," the committee's chairwoman, Liberal Democrat Assembly Member Caroline Pidgeon, said.
"The question is, when will passengers start to see noticeable improvements to their journeys?
"With passenger numbers at record levels and several line upgrades behind schedule it's time for an in-depth look at the service Londoners get, the improvements we've seen so far, and ways to get the upgrades back on track."
Unhappy passengers will get the chance to vent their grievances at public hearings on 17 May and 14 June.