A contraflow has been put in place on Preston New Road after protesters climbed onto a tanker at the fracking site, say police.
Police are warning drivers in the area to expect delays after the tanker was stopped on the Kirkham bound carriageway.
A police spokesman said: "Please be aware of a contraflow in place at the entrance to the fracking site.
"A tanker is stopped and blocking the carriageway due to campaigners having climbed onto it and a number of campaigners being stood in front of it.
"Please be aware of possible delays."