A merged unit of officers from Durham and Cleveland Police forces will save almost £400,000 in its first year of operation, senior officers have said.
The Specialist Operations Unit (SOU) shares working on roads policing, firearms incidents and vehicle thefts.
Staff work from two headquarters in Spennymoor in County Durham and at Wynyard, near Hartlepool.
The project is due to be expanded, with police vehicles displaying the crests of both forces.
Cleveland's chief constable Sean Price said: "The benefits of collaboration are clear to see - cost-effective policing while delivering a seamless service to members of the public.
"By harmonising training, policies and procedures in these specialist areas, both forces can operate more efficiently."
Durham chief constable Jon Stoddart described the unit as "unique".
"Collaboration between forces is seen as the key to maintaining an efficient policing service which is also value for money," he explained.