Sixteen different Community Speed Watch groups have been deployed across the county, to mark Project EDWARD (European Day Without A Road Death).
They will be monitoring speeds at various locations throughout the day in both 20mph and 30mph zones.
Anyone recorded to be travelling at speeds of 24mph or more in a 20mph zone or 35mph or more in a 30mph zone will receive a warning letter from North Yorkshire Police.
The force will also be keeping a close watch on the recorded data, and may take enforcement measures if a persistent or extreme offender is identified.
The groups taking part are based in Allerston and Weaverthorpe in Ryedale, Briggswath and Ruswarp in Scarborough, Stillington in Hambleton, Tockwith in Harrogate, Eggborough in Selby, Embsay, Carleton, Cononley Village and Cononley Lane, Cononley, in Craven, Gilling West in Richmond and Bishopthorpe Village, Bishopthorpe Road, Fulford and Knapton in York.
Jamie Smith, Community Speed Watch Co-ordinator for North Yorkshire Police, said: “The record turnout by groups across the county today is extremely encouraging – it shows how much people care about reducing speeding and improving road safety in their communities.
“Project EDWARD also enables our local Community Speed Watch groups to be part of something really big and make a huge difference, not just within the communities they serve, and not just in North Yorkshire, but across an entire continent.
“We’re very grateful to everyone who has volunteered for such an important cause today, and throughout the rest of the year.”
Community Speed Watch groups have been operating in North Yorkshire since 2016, following a pilot the year before.
Its main aim is to draw drivers' attention to speed limits in areas where communities feel it is affecting their quality of life and to educate them about the impact of their actions.
It was developed after a public consultation run by the Police and Crime Commissioner in July 2014 which showed that four out of five residents were concerned about road safety in North Yorkshire, and that 72 percent of people felt that more should be done to improve road safety through enforcement or education.