A drunk driving checkpoint conducted at the Casco Bay Bridge for 2½ hours resulted in five drunk-driving arrests after police checked more than 300 vehicles.

The checkpoint was operated between 11:15 p.m. Saturday and 1:45 a.m. Sunday.

Police with enhanced training in drunk driving enforcement were working on a special assignment funded by the Maine Bureau of Highway Safety. The Regional Impaired Driving Enforcement (RIDE) program in Cumberland County conducts specialized enforcement programs at different locations throughout the county.

Officers funded by the RIDE program worked alongside officers from Portland and South Portland police to conduct the roadblocks.