The proposed demonstration would see individuals carry flags and banners on viewpoints along the M8 between Glasgow and Edinburgh on Saturday, April 7.
The organisers, calling themselves YesM8, said the event was “about being seen” and was not intended to cause traffic disruption. They hope flags could be seen from 70 crossings along the route and are hoping to recruit “local co-ordinators”.
But some have expressed concern over the stunt, claiming it would be a distraction to drivers and could potentially lead to accidents.
A Police Scotland spokeswoman told The Scotsman: “However well-organised and stewarded, large gatherings of people on motorway overbridges could be distracting for drivers approaching at high speeds, as well causing an obstruction to travellers on the overbridges and side roads.
“It is an offence under the Roads (Scotland) Act 1984 to hang or fly items such as banners and/or flags from the overbridge structures, or to affix them to road signs. This is to prevent unnecessary distraction to or over-reaction by motorists on these high speed roads, as well as to avoid these items falling onto the road itself causing danger to approaching traffic.
The spokeswoman added officers would work with the group to “facilitate the safe, lawful and peaceful assembly of the participants so that road travellers are not distracted, impeded or otherwise obstructed.”
A spokesman for YesM8 said: “We met them earlier and understand the rules.”
The planned event has divided opinion among independence supporters. Former SNP MSP and Scottish Parliament presiding officer Tricia Marwick tweeted: “If they want to do something then get out leafleting or knocking doors.”
The group said in a statement yesterday: “Just for a little clarity for the naysayers. This is about visibility. This is not about shutting down roads and junctions and causing chaos. We want lawful gatherings on footpaths over the M8.”
YesM8 claims it was inspired by the work of another grassroots campaign, Bridgesforindy, which shares pictures of saltires flying from various crossings.