Mark Ruskell, who represents the Mid Scotland and Fife region, said at present there is a “postcode lottery of uncompleted patchworks of part time 20 mph zones across our towns”.
This, he insisted, it was not enough to protect pedestrians, saying: “Children and the elderly are being put at uneccessary risk of injury and death by our failure to deliver consistent speed reduction where people live.”
Mr Ruskell plans to introduce a member’s bill at Holyrood to make 20mph the default speed limit for residential area, instead of 30mph.
It comes after the Greens used Freedom of Information to obtain data showing a massive variation in the number of 20mph zones in different local authorities
Clackmannanshire Council said all its residential streets have a 20mph limit, while Edinburgh City Council said the “majority” of streets are covered, with a further 810 zones planned.
The Green MSP said: “I believe we need to change the law so that 20 rather than 30 mph is the default speed limit in residential areas, and it’s my intention to bring forward a member’s bill in the Scottish Parliament in the coming months to do just that.
“With lower speed limits, you hugely increase the chance of surviving after being hit by a car. By making 20 rather than 30 the default, we can make built-up streets safer.
“There are stories of frustration from communities across Scotland where reducing speed limits has proved a real struggle, despite the obvious benefits to safety and public health. The pace of change is too slow, so new legislation is needed to make it easier for councils to reduce speed limits consistently.”