Horses will also be outlawed from the route - the B6601 - which connects to junction 35 of the motorway near Carnforth.
The road was previously part of the motorway network and was designated as the A601(M) until two years ago.
However, when it was reclassified, the regulations prohibiting people and non-motorway vehicles ceased to apply - although they were later reintroduced on a temporary basis and are highlighted on roadside signage.
Lancashire County Council’s cabinet has now approved a new traffic regulation order to reinstate the rules permanently along the single carriageway route - which is accessed from the B6254 Kellet Road - amid concern that people could accidentally or intentionally end up on the M6.
There are no footpaths on the road and cabinet member for highways and transport Charlie Edwards told the meeting where the order was given the green light that it “doesn't really look like it's the kind of road which anyone would try and venture down - and now we have made it legally impossible for you to do so”.
He added that it was “a matter of public safety”.
County council leader Phillippa Williamson, who represents the Lancaster Rural North division in which the route lies, said that locals would be “reassured” by the return of the ban.
“It does worry some residents…that [people] could end up on the M6 by mistake,” she explained.
The southern section of the A601(M) was downgraded to a B-road after the construction of a new Porsche garage on the route, so that a reduced speed limit of 40mph could be introduced in order to ensure safe a entry and exit to and from the facility.
A separate access point was created specifically for pedestrians and cyclists, so that they did not have to use the B6601.
Also known as Leapers Wood Road, the reclassified route leads to a roundabout where the only options are to join the M6 in either direction, the remaining northern section of the A601(M) - or to head back along the B6601 to Kellet Road.
One objection was received to the proposed change, on the basis that there are plans to downgrade what is left of the A601(M) in order to reduce maintenance costs. However, that proposal is subject to approval by the government.
County Hall says that it will consider revoking the new order for the B6601 should a non-motorway exit be introduced from the junction 35 roundabout in future.