The scheme could be a risk to those who are blind or partially sighted.
New street schemes which merge traffic and pedestrian areas could put blind people at risk, a charity has warned.
The Guide Dogs for the Blind Association warned it may take legal action against councils who construct shared spaces in town and city centres.
The concept of removing traffic lights, pavements and heavy signage was developed in Europe to create social spaces and reduce traffic build-up.
The design is being adopted by councils in Edinburgh, Stirling and Orkney.
The system is based on no-one having right of way, forcing motorists, pedestrians and other road users to make eye contact and decide among themselves when it is safe to proceed.
As a result, buses, taxis and pedestrians all share the same space.
Urban design consultant Ben Hamilton-Bailey said: "The more you add regulation control systems in towns, strangely, the less safe it becomes because then drivers do not engage with their surroundings.
"It's premised on the notion that it's more sensible to treat drivers as if they were intelligent, rather than to treat them as if they were idiots."
However, Jane Hurseburgh from the Guide Dogs for the Blind Association told BBC Radio Scotland the system posed dangers to people who were partially-sighted or blind.
She said: "We take this very, very seriously. In fact, this is an issue that we have to win for blind and partially-sighted people.
"We've taken legal advice and we may find ourselves in the courts with local authorities because we don't actually think that they're complying with the new disability equality duty."
Janet Scott, who uses a cane and a guide dog, said that since the system had been adopted in Stirling, she had felt unsafe in the city centre.
She added: "I find it quite dangerous. I'm finding that I actually now avoid this area of the city centre and go out of my way to find a safe place to cross.
"Before the shared surfaces, it was easy enough for me to identify the kerbs.
"Now it's difficult to locate the safe areas and identify what is the pedestrian area and what is the traffic area."
Les Goodfellow from Stirling Council said the local authority was taking another look at the impact of the shared space on locals.
He added: "We were very conscious of the fact that there were a whole range of users in this space that needed to be considered.
"As part of the design process, we involved the local visually impaired group and took on board a number of the issues that they raised with us and have incorporated them into the final design.
"We have incorporated a number of features in the design like the tactile paving to identify these spaces as different for the visually impaired."