Operation Snap started last October in north Wales, encouraging drivers to upload evidence to the police website.
So far, the force has dealt with 129 cases as a result of footage submitted.
The operation will link up with the Go Safe partnership to operate across Wales.
Insp Dave Cust, of North Wales Police Roads Policing Unit, said Operation Snap had saved police about 12 hours' work per case, as investigating an allegation of bad driving could take up a lot of resources.
He added footage could be used to prove innocence as well as guilt.
"There was a woman who went through a green light and hit a car. Two members of the public said she went through a red light and she was going too fast. The camera proved differently," he said.
"It's proper, reliable evidence."
Footage has to be unedited and include the whole journey, not just the incident. Members of the public are also told not to post it on social media, or to remove it if it has already been posted.
Police forces from other parts of the UK, Australia and Hong Kong have been in touch about the scheme.
The North Wales team receives three to four submissions on week days and up to 10 at weekends.
All four police forces in Wales are to start using dashcam footage recorded by the public to investigate driving offences following a successful pilot scheme by North Wales Police.