Campaigners are to lobby the Government to try to get the decision to approve a £5 million transport scheme overturned.
County Hall has approved a project that will see bus lanes introduced along the A426 from Glen Parva into Leicester.
The plan is intended to ease congestion and speed up journey times.
Despite more than 4,000 people signing a petition opposing the plan it was backed by the council's cabinet.
The protestors have vowed to fight on to prevent the project, which they argue is a waste of cash that will not deliver significantly shorter bus journey times.
They are also worried about traffic delays during the eight-month construction period.
Richard Johnson, head of Glen Parva and Aylestone Action Group said: "We feel a bit flat because we thought our campaign was a good one.
"We tried to win the argument locally and persuaded two cabinet members to vote against it, but it still went through.
"We won't give up, though, because our arguments are still valid."
He said he would write to transport minister Norman Baker and ask South Leicestershire MP Andrew Robathan to lobby the Department of Transport, which is contributing £2.5 million to the project.
Mr Johnson said the group was also considering challenging County Hall's decision in the courts through a judicial review.
He said there would be protests in the new year.
"By then, we will be re-energised," Mr Johnson said.
"We have done protests already but they have not had the desired effect. We might take it to the next level.
"It wouldn't take too much to bring the traffic to a stop."
He stressed any protest was not intended to alienate motorists and no action would be taken without consulting police, but said: "We just want to demonstrate the disruption we think the scheme will cause."
Mr Robathan said of the county council's decision: "I am very sorry about that because I think it is the wrong decision.
"But I have said all along it is not my decision."
He said he would consider speaking to the transport minister if requested.
County Hall is putting £600,000 into the scheme which will also see improvements at key junctions and upgraded buses.
County Hall transport spokesman Coun Lesley Pendleton said: "I know there has been a lot of opposition but this really will be better in the long term.
"The Government has already looked at the scheme and decided it was one worth backing."
Leicester City Council is putting £1.5 million into the bus scheme, with a further £300,000 coming from bus firm Arriva.
City mayor Sir Peter Soulsby has yet to make a final decision on the project but has said it was county council-led and that the county's view would shape his own."