A shuttle bus between Wantage and Faringdon could be launched while the A417 Challow Road is shut for four-month long bridge works.
The plans were raised by Network Rail during a packed meeting for residents at Faringdon Corn Exchange on Tuesday night.
Crowds of more than 100 people from Wantage, Faringdon and the villages piled into the building with Network Rail and Oxfordshire County Council bosses.
A petition signed by more than 1,032 people calling on plans to shut the major route to be dropped was handed over to the county’s cabinet member for transport David Nimmo Smith.
Faringdon town councillor Alex Meredith, who organised the meeting, said: “People are not entirely satisfied but it was constructive.
I still think it will be extremely tough for commuters effected including myself and the communities on the route but my impression was it will be hard to find an alternative solution and it was good to understand that.”
The A417 Challow Road bridge is to shut from September 6 to December 5 for Network Rail to raise the bridge to install electric wires over the train line below.
The project is part of the £2bn electrification of the Great Western Mainline.
A diversion route will run along the A338, A415 and A420.
Campaigners raised their hopes when Network Rail announced a u-turn in May on similar plans to shut the A338 Wantage Road bridge at Grove’s Volunteer pub.
It was due to be closed for six months until the rail company agreed to build a new bridge off-site rather than alter the existing bridge.
But Network Rail spokesman Victoria Bradley said: “Unlike Wantage Road, Network Rail does not own sufficient land at Challow Road to build a separate bridge.”
She added: “We have committed to build a temporary bridge for services, pedestrians and cyclists, and are currently investigating options to run a shuttle bus service for the duration of the work.”
It is understood the shuttle bus would run between Faringdon and the A417 Challow Road on one side of the bridge for people to cross the bridge and catch another shuttle to Wantage.
Wantage and Grove Campaign Group leader Julie Mabberley said: “It is a reaction of frustration but it is like trying to move a stone wall.
“But the good news is Network Rail said they will put in a shuttle bus service.”
Kingston Lisle resident Brian Sadler, 71, raised concerns that the diversion routes around the road could not cope with the traffic.
Mr Sadler said: “It wasn’t very satisfactory because there are a lot of problems going to be created.”