main line railway for the people of Oxfordshire and the Midlands. This deal demonstrates that real improvements to rail services can be paid for without public subsidy by attracting people out of their cars and on to trains." Network Rail said its investment will be reimbursed by a 'facility charge' over the next 30 years, by Chiltern Railways, whose franchise expires in December 2021, and then by the future franchisee. The infrastructure upgrade was carried out by main contractor BAM Nuttall, in partnership with Jarvis and WS Atkins. Passenger services Chiltern Railways are the main operators of the route, however parts of the line carry services by other operators: West Midlands Trains operate local services in the West Midlands area between Birmingham, and Leamington Spa as part of the Snow Hill Lines, and CrossCountry operate some services from either Birmingham (joining the line at Bordesley junction) or Leamington (joining from the Coventry-Leamington line) and running as far as Aynho Junction where they diverge towards . Great Western Railway also operate a few services to Banbury via Oxford. Weekday off-peak service pattern At May 2011: Rolling stock Passenger trains are operated by: Connections Connections are available at: Birmingham Snow Hill, to and Worcester, and Midland Metro to West Bromwich and Wolverhampton. Birmingham Moor Street, to Leamington Spa, to Stratford-upon-Avon, , , and The North Banbury, to , Reading, and Princes Risborough, to West Ruislip/South Ruislip, to the LU Central line to Oxford Circus London Marylebone, to Aylesbury and the LU Bakerloo line to Oxford Circus Birmingham New Street, Birmingham's main station, is a five-minute walk from Moor Street; Baker Street, where several London Underground lines call, is a five-minute walk from London Marylebone. Future Battery/diesel trains In September 2021, Class 168/3 HybridFlex battery/diesel trains were introduced. These train emit lower emissions. The trains operate on batteries giving zero emissions when in stations or sensitive urban areas. Electrification No section of the line is electrified, but in 2010 the then chairman of Chiltern Railways, Adrian Shooter, indicated that electrification was being considered, though not in the immediate future. He added: "We could do some very interesting things with high-acceleration EMUs and possibly some further infrastructure work". Other plans There are several proposals: The restoration of the quadruple track between South Ruislip and West Ruislip, allowing trains to call at both stations without blocking the line. Triple track currently exists at West Ruislip,