In a statement, the PSNI said: “It is hoped disruption will be kept to a minimum, however, motorists should be mindful of increased footfall in the village between 9am and 3pm.
"If you are planning on attending the various family events within Hillsborough Castle and Gardens, please leave extra time for your journey and follow parking advice from officers on the “ground.
"For those who are not travelling to the event, please be aware of large volumes of traffic off the A1 towards Hillsborough Road roundabout and seek an alternative route where possible.”
Meanwhile, Trafficwatch NI is advising road users of a parade that is taking place in Dromore this evening (Friday) 6.30pm -10:30pm.
"The parade will be taking place from Hillsborough Rd through the town centre and taking in Circular Rd and Banbridge Rd.
"No HGVs will be permitted into the town due to numbers involved. Diversions will be in place.”