Rail upgrades in the South East costing more than £2 billion will get underway this week.
Network Rail announced the investment to try and accommodate for increasing numbers of commuters coming into the capital from Kent and Sussex.
The 5 year plan to improve stations, introduce more trains and 20% more seats will get underway this week.
Some routes have seen a 50% increase in passengers over the past 10 years, so Network Rail now hopes to succeed in connecting Kent and Sussex with London before 2019.
This will form part of a wider programme to deliver an extra 115,000 seats a day into the capital.
Network Rail's Dave Ward, said: "The growth we are managing now is phenomenal - Southeastern and Southern already run more than 2,000 trains each every day - and this has given us a real opportunity to improve the railway in Kent, Sussex and south-east London."