Dublin Bus will lose iconic routes including the 46A under a radical restructuring of the network.
Major changes will see all routes re-numbered, the creation of seven 'super frequent' routes into the city and a move to a new two-fare system.
The measures were announced by the National Transport Authority (NTA) and are the most radical redesign of the capital's bus system ever undertaken.
The NTA insists that the changes will open up the city, allowing people to access more frequent services and result in time savings, but it will represent a "huge change" for passengers.
Under the proposals, the level of bus service across the city will increase by 27pc, and 11 new orbital routes which will operate every 15 minutes or more will be introduced.
The main changes are:
The NTA also announced plans for a new two-tier fare structure - one will cover short journeys, while a second 90-minute fare is proposed where a customer can use any public transport system (bus, Dart or Luas) for a journey, subject to the last leg commencing within 90 minutes of the start of the overall trip.
Some passengers may be forced to change buses to access their destination, but the NTA said the benefits would be faster, more reliable journeys.
"The number of people living within 400m of a service that operates every 10 minutes or better, will increase by 35pc from 480,000 to 650,000," it said.
"The number of people living within 400m of a service that operates every 15 minutes or better, will increase by 31pc from 765,000 to almost one million.
"The number of jobs or college places situated within 400m of a bus service operating every 10 minutes or better will increase by 18pc from 540,000 to 640,000."
Services will be organised on the basis of six categories: spines; spine branches; orbitals; other radials; locals; and peak-only services. The route numbering system will reflect these categories.
"Spines, for example, are designated by the letters A to G, which separate into branches further out from the city. Each bus on a spine service would be designated by a letter followed by a digit, like A1," the NTA said.
All 'A' buses will pass through Terenure, for example, with the A1 continuing to Knocklyon and the A2 to Tallaght.
Public consultation gets under way on July 16, and will run until September 14.
The redesign is proposed because the network and fare structure is considered to be overly complex. The NTA wants to make it easier to use, and more attractive to passengers.
But it will involve major changes for passengers.
The 46A, which runs from Dun Laoghaire in south Dublin to the city centre, will be renumbered as the E2. Passengers will not have to interchange with other services.
However, the 31 from Howth to the city centre will change. It will be replaced by the N6, which is one of the new orbital routes. Passengers will transfer from the N6 on the Malahide Road, before getting a bus on the 'D' spine.
Those using the 77A from Ringsend to Citywest will have to switch twice. They will board the W8, an orbital route, at Citywest, before switching to the A or D spine at Tallaght. They will change again on the 'O' orbital route on the canals, before continuing to Ringsend.
NTA chief executive Anne Graham said: "The current system of bus routes and services in Dublin is complex, with about 130 different bus routes forming the network. Currently the network is radially focused, with most routes emanating outwards from the city centre.
"As a result, many bus journeys can only be made by firstly travelling into the city centre on one radial route, and then taking another radial bus service out.
"We believe that a system with greater scope for interconnection between routes, and where passengers don't necessarily have to travel to the city centre, is one that would be far more attractive and convenient."
More buses will be required, but the NTA said the costs were not yet known. It hopes to introduce the changes from next year, after the public consultation period ends.
It urged people to engage with the process.