Bristol Temple Meads and Parkway get extra tracks
Two new tracks between Bristol's main railway stations will provide the capacity to "grow" local rail services, the city's assistant mayor has said.
Network Rail said this would double the capacity between Temple Meads and Parkway stations, would allow more trains to run and cut journey times.
Councillor Mark Bradshaw said it would make it easier to open the Henbury loop and cross Bristol routes which campaigners have long called for.
The work is due to start in December.
"It's consistent with the [under construction] fast electric services into London and south Wales and that very important CrossCountry link to the Midlands and HS2," Mr Bradshaw said.
Network Rail said the £33m investment would help with the demand for rail transport into and out of the city which it says is set to rise by 50% within a decade.
"To help meet this demand, the number of lines between Temple Meads and Parkway stations will be increased from two to four through Stapleton Road and Lawrence Hill [stations]," a Network Rail spokesman said.
"The extra lines will also enable an increase in freight services."
The Henbury loop, which closed nearly 50 years ago, connects Avonmouth, Shirehampton, Sea Mills, Lawrence Weston and north Bristol
Campaigners hope the circular route around the city, and re-opening the Portishead to Temple Meads line to passengers, would help provide a viable Bristol rail metro.