Campaigners are urging more people to back a petition to lobby the government to scrap tolls at the Humber Bridge.
The Humber Bridge tolls are among the highest in Britain
Protest group Humber Action Against Tolls says the charges adversely affect the local economy and punish hospital patients who have to use the bridge.
More than 5,000 people have signed the online House of Commons petition, which closes on 2 January.
Four councils have commissioned research aimed at persuading the government to scrap the charges.
North Lincolnshire Council leader Mark Kirk said: "We are seeking to commission research that will show the tolls are doing the area no favours.
"But we need the help of as many residents as possible.
"More than 5,200 people have taken a few minutes of their time to sign the petition. That's good but we need more names to show the strength of feeling on this issue."