Constable Jaimee McDonald, of Dunedin, said both drivers and horse riders had a right to use the road and shared a responsibility to consider each other's safety.
It was particularly important that people knew how to drive around horses as daylight saving and the warmer weather brought more users out on to the road.
Mosgiel police had already received several complaints, including one each from a driver and a rider involved in the same close call, she said.
It was also timely to remind people of driving safely around horses, following a recent incident in Auckland where a girl's horse had to be put down after it was clipped by a truck.
The 15-year-old and her friend were riding on a rural footpath, but the driver's speed and proximity spooked the animal and its back leg slipped on to the road and into the rear of the truck.
Const McDonald said it was difficult to actively police all roads, and also difficult for riders to note down registration plates as they were usually too busy trying to get their horses under control at the time of an incident.
She said Mosgiel police were keeping an eye on rural roads around the Taieri, but educating drivers and horse riders was the key to safer sharing of roads.
The key message was for drivers to pass horses slowly and wide, she said.
Passing wide helped minimise the likelihood of a horse jumping sideways into the pathway of a vehicle.
The rule applied to both motorised vehicles and cyclists, as most horses would react more to a cyclist speeding past than a car, she said.
All road users needed to courteous.
''This applies to horse riders and motorists.''
Horse riders needed to ride on the left side of the road, and wear high-visibility clothing to ensure they could be seen.
