Town councillors have given their backing to the "20 is plenty" campaign, which is seeking to persuade Shropshire Council to reduce speed limits across the county.
A majority of councillors supported a motion on the issue at Monday's meeting of the full council, proposed by Councillors Pam Moseley, Julian Dean, and Nat Green.
Councillor Dean said: "What we would like to see happen is Shropshire Council take seriously the idea of introducing a county-wide scheme.
"The experience we have heard about from the conference held in September is that this is a very successful way of reducing not just fatalities but also injuries.
"It makes road considerably safer, safer than you would think for that small difference because it massively increases thinking time for drivers and pedestrians."
The proposal is that 30mph zones would become 20mph by default. They would only be made 30mph by exception.
Councillor Nat Green said he hoped the move would put more pressure on Shropshire Council to consider introducing the changes.
He said: "I am very pleased the town council has passed it. It just means a bit more pressure on Shropshire Council to implement 20mph zones which I think would be of a great benefit, particularly in places like St Michael's and Coton Hill."
Councillor Green said the best way to see if the limits would be a benefit is to try them.
The motion stated: "Shrewsbury Town Council recognises the benefits associated with a 20 miles per hour speed limit in residential areas, rather than a default limit of 30mph, which exists in most parts of the town, and county.
"There are fewer fatalities and injuries, greater survivability in traffic collisions, improved air quality, reduced fuel use, and a greater willingness of the population to walk or cycle - which has associated health benefits.
"The town council therefore supports the "20 is Plenty" campaign and asks that Shropshire Council investigates how best the 20 miles per hour limit can be introduced to the streets of Shrewsbury."
The council is now expected to write to Shropshire Council to formalise the request.
Earlier this year a number of people attended a conference at Shrewsbury's Theatre Severn hosted by the "20 is Plenty" campaign.
Speaking at the time conference organiser John Whitelegg said: “There is robust scientific evidence that 20mph is a highly effective public health intervention, and increases the number of people walking and cycling which in turn reduces car use, congestion, greenhouse gas emissions and improves air quality.
“Many of us have argued for five years or more for a Shropshire-wide 20mph limit."
"Warrington Borough Council reports a 25 per cent decline in collisions as a result of its 20mph policy and the Scottish Parliament is considering new legislation to make 20mph general throughout Scotland on residential roads."