TfL will soon start running the stopping services between Paddington mainline and Reading ahead of the service becoming part of the Elizabeth line.

The services, currently operated by Great Western Railway, will be operated as TfL Rail from December 15 when it becomes the Elizabeth line, which opens through central London.

READ MORE: Reading routes to be transferred to Crossrail as Great Western Railway begin changes

Under TfL Rail, the current service frequency of four stopping trains an hour in the peak between Paddington mainline and Reading will be maintained using the new Elizabeth line trains.

Two trains an hour will run during the off-peak, as is currently the case.

The service replaces part of the Great Western inner suburban route, some fast services will continue to be operated by GWR from Reading, Twyford, Maidenhead and Slough to Paddington.

READ MORE: New Great Western Railway timetable made public for the first time

TfL zones do not apply to stations beyond West Drayton, but for the first time, customers will be able to use pay as you go with contactless across the route all the way from Paddington to Reading.

To ensure that it is introduced smoothly to customers, contactless ticketing will come into effect in line with the annual fares revision on January 2, 2020.

Between December 15 and January 2, existing ticketing arrangements will apply and TfL Rail fares will remain at the same price as the current GWR fares.

However, in line with TfL's wider policies, children under 11 who are accompanied by an adult, as well as customers who are eligible for the Freedom Pass, will be able to travel for free to Reading on the new TfL service.

READ MORE: First pictures of new TfL trains operating in Reading from December

Once introduced, adult pay as you go fares to/from stations between Iver and Reading are anticipated to be cheaper or in line with standard single and return fares along the line.

All fares will be set in line with Department for Transport policy and confirmed nearer the time.

Pay as you go with Oyster will not be extended to services beyond West Drayton, due to limitations with the system, which is now more than 15 years old.

Millions of journeys in and around London are already being made using contactless every day; with 60 per cent of rail pay as you go journeys made using contactless.

Station improvement work is being delivered by TfL and Network Rail at all stations between Paddington mainline and Reading, including lifts providing step-free access, new station entrances, improved customer information systems, signage and waiting rooms.

Howard Smith, operations director for TfL Rail, said: "Starting TfL Rail services to Reading is another step towards opening London's new railway, the Elizabeth line.

"Customers will see staff at every station, and improvements being made to stations along the route including the installation of lifts to provide step-free access, they will also be able to enjoy the convenience of pay as you go contactless payments all the way to Reading."

Network Rail will be undertaking some Christmas engineering work between Tuesday, December 24 and Friday, December 27.

A reduced service will run on the Tuesday and Friday with replacement buses between Slough and Hillingdon. There will be no service on the entire line on Christmas Day and Boxing Day.