The 1.4km tunnel, which links Newham to the Greenwich Peninsula, was first announced in 2012 and is expected to save commuters up to 20 minutes during peak times.
The project, delivered by Transport for London (TfL) and Riverlinx Limited, has increased the number of buses able to cross the river from six to 21 per hour.
The new bus routes include the Superloop 4, which will connect south-east London to Canary Wharf for the first time.
The route will run every eight minutes during weekdays and every 15 minutes at weekends.
The new cross-river bus routes serving Greenwich, Newham, and Tower Hamlets will be free for pay-as-you-go users for at least 12 months.
A cycle shuttle service has also been launched, which will be free for at least a year.
The Mayor of London, Sadiq Khan, said: “The new Silvertown Tunnel will transform travel in the south and east of our city, particularly across the River Thames, and will help to address the chronic congestion and poor air quality around Blackwall Tunnel.
“The new tunnel will reduce journey times, help to manage pollution levels, and improve cross-river public transport.”
A toll charge has been introduced for the Silvertown and Blackwall tunnels between 6am and 10pm, seven days a week.
According to TfL, this is to manage traffic levels and cover the costs of building and maintaining the Silvertown Tunnel.
A range of concessions and discounts are available, including a 50 per cent discount for low-income residents in the surrounding areas.
The land previously used for the construction of the Silvertown Tunnel will now be used for the Thameside West development, which will deliver 5,000 new homes, strategic industrial land, and a new DLR station.
This forms part of the Mayor of London’s wider vision for the regeneration of the Royal Docks, which will see over 36,000 new homes built and 55,000 new jobs created across east London.
Andy Lord, London’s transport commissioner, said: “The new Silvertown Tunnel is vital to supporting growth in east and southeast London and boosting cross-river bus services.
“Supported by the user charges for the Silvertown and Blackwall tunnels, the new tunnel will also help reduce congestion and associated air quality issues around the Blackwall Tunnel, making journeys faster and more reliable.”
